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Mendel in America: Theory and Practice, 1900-1919

by Diane B. Paul and Barbara A. Kimmelman

Copyright © 1988 by the University of Pennsylvania Press.

(This article originally appeared in The American Development of Biology,
edited by Ronald Rainger, Keith R. Benson and Jane Maienschein, (University
of Pennsylvania Press, 1988), pp. 281-310. It appears at MendelWeb, for
non-commercial educational use only, with the kind permission of the authors
and the University of Pennsylvania Press. The entire volume has been
reprinted by, and is currently available from, Rutgers University Press.
Although you are welcome to download this text, please do not reproduce it
without the permission of the authors and the University of Pennsylvania
Press.)

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In September 1903, Willet Hays addressed the first meeting of the American
Breeders Association (ABA). A founding member and guiding spirit of the
association, Hays was then a professor of agriculture at the University of
Minnesota and director of the state experiment station; two years later he
would be appointed Assistant Secretary of Agriculture. In his opening
remarks, he lamented:

     Science has been content to remain at the task of providing for
     the ten thousandth time that Darwin's main contention is true but
     has allowed the great economic problems of evolution guided by man
     to remain almost a virgin field. Only recently have such men as
     Galton, Mendel, de Vries, Bateson and a few others, entered upon
     comprehensive lines of research and many of these have hardly
     grasped the vast economic interests which are at stake, nor have
     they seen the open doors of opportunity which might be entered by
     cooperation with the men who control the breeding herds and the
     plant-breeding nurseries.[1]

Hays's opinions were widely shared. Excited by the developments in what
would soon be called "genetics," most ABA members agreed with William
Bateson that: "At this time we need no more general ideas about evolution.
We need particular knowledge of the evolution of particular forms."[2]
Francis Galton's law of ancestral heredity, Gregor Mendel's laws of
dominance, segregation and independent assortment, and Hugo de Vries'
mutation theory were all greeted enthusiastically. Because the ABA had a
varied membership, there was more than one source of interest in the new
discoveries. The chief factor, however, was a belief that these laws could
readily be used to improve artificial selection. Some association members
were particularly concerned with selection in humans. A greater emphasis on
eugenics was promoted by Charles Davenport, who argued that "society must
protect itself; as it claims the right to deprive the murderer of his life
so also it may annihilate the hideous serpent of hopelessly vicious
protoplasm."[3] The majority, however, were less concerned to improve humans
than grapes, hogs, beans, or, especially, corn. Their primary concern, in
Deborah Fitzgerald's phrase, was with "the business of breeding."[4]

Who were these early enthusiasts for Mendel? Why did they accord his work
such a warm reception? How did their response compare with that of
biologists who interests were principally descriptive or theoretical, rather
than applied? And how did their concerns with agricultural practice inform
their program of research?

We find that particular economic pressures and practical demands on
agricultural breeders, within the context of late nineteenth-century
agricultural reform, encouraged actively interventionist, experimental
techniques. These included hybridization and the crossbreeding of
varieties.[5] In particular, a perceived crisis of wheat overproduction in
the 1870s prompted the United States Department of Agriculture (USDA) to
elaborate a policy of diversifying agricultural products. USDA officials saw
creation of novelty as crucial to this program. More specifically, they
aimed to increase variation and produce stable hybrids. In the 1880s and
1890s, the department expanded its own experimental breeding work along
these lines and, significantly, promoted such work at state agricultural
colleges and experiment stations.

Focusing on experimental creation of variation and the inheritance of
particular characters, the work of scientists at agricultural institutions
converged with that of an international group of botanists and hybridists
interested in evolutionary problems (including de Vries and Bateson). After
1900, these contacts provided American agriculturalists with ready access to
Mendel's work, while their technical and intellectual background prepared
them to receive it enthusiastically. The strength of breeding and genetics
programs at agricultural colleges and experiment stations in the decades
that followed insured the pursuit of genetics at publicly supported
institutions characterized by simultaneous commitments to the ideal of basic
research and the practical demands of economic agriculture. The early work
on hybrid corn, presented here as a case study, illustrates the importance
of this context for the direction of genetics research.

Who Were the "Breeders"?

From 30 August to 2 September 1902, the International Conference on Plant
Breeding and Hybridization met in New York City. Reviewing the conference
for Torreya, Walter Cannon noted that, "generally speaking, the plant
breeders had not taken advantage of the Mendelian theory in their work, and
some of them did not know of Mendel or of his experiments before the
Conference."[6] But they left it as converts to the new genetics. C. W.
Ward, a carnation grower, was one of the commercial breeders in attendance.
His remarks attest both to the degree and source of the excitement with
which such breeders greeted Mendel's work: "I have known nothing of Mendel's
theory or law until the day before yesterday," he said, "but what I have
heard here regarding Mendel has awakened an increasing interest in the work
of hybridizing and I shall secure his books and read them with the greatest
interest, for if there is a fixed rule by which I can produce six inch
carnations on four foot stems I certainly wish to learn that rule."[7]

One of the foreign visitors, speaking on "Practical Aspects of the New
Discoveries in Heredity," was William Bateson.[8] Following the talk,
Liberty Hyde Bailey of the state agricultural college at Cornell recommended
Bateson's just published book, Mendel's Principles of Heredity: A Defence.
9"If you wish to follow this ['the Mendelian hypothesis'] with the greatest
degree of accuracy, you should get Mr. Bateson's recent book," he urged,
adding that: "I expect to use this book as a basis for all our work in plant
breeding."[10] His advice was apparently heeded. On 3 October, Bateson wrote
excitedly to his wife: "At the train yesterday, many of the party arrived
with their 'Mendel's Principles' in their hands! It has been 'Mendel, Mendel
all the way,' and I think a boom is beginning at last. There is talk of an
International Assn. of Breeders of Plants and Animals and I am glad to be
right in the swim."[11]

Commenting on this letter, Garland Allen suggests that: "It may perhaps seem
curious that plant and animal breeders, with their primary concern for
practical results, would have taken more readily as a group to Mendel's
theoretical presentation than many of the more academic biologists."[12] He
is certainly right to note that Mendelism made sense of breeders' results --
both their successes and failures -- and was thus greeted as a means to
improve the efficiency of breeding practice.[13] The distinction between
breeders and academic biologists is, however, somewhat misleading if the
former are equated with farmers or "seedsmen."[14] To be sure, some
"practical breeders" such as L. H. Kerrick and Eugene Funk were founding
members of the ABA. This group also played an important role in garnering
political support for the work of agriculturalists at state institutions,
which was crucial to the establishment of genetics as an academic
discipline.[15] But the enthusiasts referred to by Bateson were mostly
scientists, not seedsmen. Of course they were scientists of a particular
kind, both institutionally and in respect to their aims. Employed at
agricultural colleges and agricultural experiment stations, rather than at
arts and sciences institutions, they were concerned with the implications of
Mendelism for practice as well as theory.

The dominant force at the 1902 New York Conference was Bateson; his lead
paper combined a straightforward account of Mendel's laws with a discussion
of their applied, and especially commercial, importance. To the breeders he
argued:

     Now when we come to the question of the significance of these
     things to the breeder and the hybridist, it will be found that the
     significance is exceedingly great. I am afraid of saying that we
     have reached a point when the practical man who is doing these
     things with a definite, economic object or commercial object in
     view can take the facts and use them for his definite advantage.
     But we do for the first time get a clear sight of some of the
     fundamentals of which he will in future work, and it cannot be now
     very many years, if the investigations go on at the present rate,
     before the breeder will be in a position not so very different
     from that in which the chemist is: -- when he will be able to do
     what he wants to do, instead of merely what happens to turn
     up.[16]

The following two papers, by C. C. Hurst (Bateson's close friend and
colleague) and Hugo de Vries, focused on Mendel as well.[17] In all, ten
participants either presented papers or made extended remarks promoting
Mendelism. Seven were Americans: Willet Hays of the Minnesota Agricultural
Experiment Station, Liberty Hyde Bailey of Cornell, S. A. Beach of the New
York Experiment Station, Walter Austen Cannon of Columbia and the New York
Botanical Garden, and O. F. Cook an W. J. Spillman, both of the USDA. If
members of this group are to be characterized as "breeders," it follows that
many breeders active in promoting Mendelism were academic biologists. Of
course they were academic biologists of a particular kind, both
institutionally and in respect to their goals. These biologists were
generally affiliated with the USDA or state agricultural colleges and
experiment stations and they aimed to combine practical public interests
with theoretical science.

Our paper details this crucial, yet historically neglected, role of this
group in introducing and popularizing Mendel's work. But we should note that
biologists with a primarily theoretical orientation were also generally
receptive to Mendelism (in sharp contrast with naturalists, who were
decidedly cool).[18] T. H. Morgan was a severe critic, but his views on
Mendel were atypical. While some biologists who employed the method of
experimental breeding (either to improve selection or to answer questions
regarding the physical basis of heredity or its relation to evolution) were
indifferent to the new genetics, few were actively hostile. Indeed, most
were enthusiastic, irrespective of whether they were employed at state
agricultural institutions or elite colleges and laboratories. Walter Sutton,
Nettie Stevens, E. B. Wilson, E. M. East, William E. Castle, Charles
Davenport, and George H. Shull, for example, were all avid Mendelians, whose
principal concerns were theoretical. The last four also belonged to the ABA.

If Allen asserts too sharp a separation between breeders and academic
biologists, Jan Sapp rejects the distinction altogether. In his view,
"breeder" is practically synonymous with "geneticist" until at least 1915,
because in the early years "Mendelian investigators recognized no
distinction between pure science and applied science."[19] But although many
academic biologists, particularly those employed at state agricultural
institutions, pursued both pure and applied research, they certainly
recognized "pure" and "applied" as categories; indeed, the proper balance
between them was a matter of intense concern. Moreover, as we have seen,
there were breeders whose interests were purely applied and geneticists who
interests were largely (in a few cases, entirely) theoretical. Eugene Funk
was not a "geneticist," nor George Shull a "breeder." The relationship
between the practical breeders and geneticists was addressed by Hays in his
opening speech at the first meeting of the ABA:

     The producers of new values through breeding are brought together
     as an appreciative constituency of their servants, the scientists.
     They are ready to aid in securing all needed means for scientific
     research in problems relating to heredity, provided the scientists
     can develop methods of research which will aid the breeders in
     more rapidly improving the plants and animals. The scientists, on
     the other hand, are ready to emerge from the cloister of species
     and genus grinding in the study of historic evolution, and
     cooperate with practical breeders in the study of breed and
     variety formation and improvement. . . . No less of an incentive,
     at least to the scientists, is the possible solution of some of
     the intrinsic problems of development in plants, in the lower
     animals, and in man.[20]

What united virtually all ABA members -- whether commercial seedsmen,
editors of farm journals, USDA officials, or researchers at state
agricultural colleges or elite arts and sciences institutions -- was their
enthusiasm for the technique of experimental breeding. Some hoped to answer
theoretical questions, others to improve agricultural practice; many aimed
to do both. But however disparate their motivations, those who used
experimental methods generally expressed a keen interest in Mendel's work.

The USDA and the Reception of Mendelism

No organization played a more important role in the dissemination of
Mendelism than the USDA. At the 1902 New York Conference, eleven of the
seventy-five participants were employed directly by the USDA; many more were
affiliated with the state agricultural colleges and experimental stations.
At the first two meetings of the ABA (1903 and 1905), seventeen of
forty-five papers were presented by USDA officials; these included the
majority of papers dealing primarily with Mendelism, such as Spillman's
"Mendel's Law in Relation to Animal Breeding" and Webber's "Explanation of
Mendel's Law of Hybrids."[21]

As early as 1901, the USDA's Experimental Station Record, which functioned
as an information clearinghouse for the experiment stations, published a
detailed synopsis of Mendel's work based on Bateson's communication to the
Royal Horticultural Society, "G. Mendel, Experiments in Plant
Hybridization."[22] The Record summarized Mendel's concepts of dominance and
independent assortment of different pairs of characters, and discussed the
significance of his statistical ratios. It also quoted Bateson's claim that
Mendel's laws were " worthy to rank with those that laid the foundation of
the atomic laws of chemistry."[23]

An abstract of Tschermak's article on the inheritance of characters when
crossing peas and beans immediately followed this report. According to the
Record, Tschermak's work tested Mendel's predictions and, while losing
something of the generality of his results, nevertheless underscored its
"importance for theoretical and plant breeding purposes."[24] A few issues
later, the Record provided a synopsis of Bateson's earlier communication to
the Royal Horticultural Society on "Problems of heredity as a subject for
horticultural investigation," which was "largely a review of the work of
Mendel and de Vries."[25]

By choosing to abstract this work in detail, and through its editorial
remarks, the Experimental Station Record conveyed to its readers a profound
appreciation of the scientific value of Mendelism and its implications for
horticultural investigation. In the years immediately following, the Record
reported both American and European work, noting obvious limitations as well
as evidence of its potential applicability to practical problems.[26] Thus,
news of Mendel's work and the experiments and controversies it prompted was
available to experiment-station personnel in every state.

The USDA also helped popularize Mendelism through its Graduate School of
Agriculture, inaugurated in July 1902 (only two months after the New York
Conference). Seventy-five students attended, of whom twenty-seven were
faculty at agricultural colleges and thirty-one assistants in the
agricultural colleges and experiment stations. According to Liberty Hyde
Bailey: "Perhaps the two agencies most responsible for the dissemination of
the Mendelian ideas in America were the instruction given by Webber and
others in the Graduate School of Agriculture at Columbus last summer, and
the prolonged discussion before the International Conference on
Plant-Breeding at New York last September."[27]

The USDA was founded in 1862, the same year as the passage of the Morrill
Land-Grant Act, which established most the country's agricultural colleges.
In the 1870s and 1880s, the federal government began to increase markedly
its commitments to agricultural research. As Margaret Rossiter has noted,
the degree of federal support is striking, given the depressed condition of
contemporary agricultural science: there had been no intellectual successes
since the development of agricultural chemistry in the 1840s and 1850s and
low enrollments in agricultural subjects persisted at state colleges.[28]
Nevertheless, the Hatch Act, funding the experimental stations, was passed
in 1887 and the Morrill Act, primarily for establishing black colleges of
agriculture, in 1890. During the same period, appropriations for the USDA
itself increased dramatically, as did the number of its employees.

These agricultural appropriation acts, reflecting greater federal
intervention in agriculture, were contemporaneous with others that signaled
an end to the laissez-faire ideology characteristic of nineteenth-century
America. Both the Interstate Commerce Act and Hatch Act were passed in the
same year; so were the Sherman Anti-Trust Act and the second Morrill law. As
the United States entered international commerce following the Civil War,
both industrial and agricultural production were thought too important to be
left to chance. The government, with the aid of various interest groups, was
now prepared to intervene in the interest of the national economy.[29]

In response to the social and economic crises that marked this period,
federal administrators and researchers advanced the cause of science-based
agriculture. They held that agricultural problems could be addressed most
effectively through the application of work in the natural and social
sciences, pursued by experts at centralized institutions and disseminated to
farmers. Their program was a response, and potential antidote, to the
campaign for structural changes advocated by populists. It also helped
decide a long-standing debate among agricultural educators in favor of those
who believed that state colleges and research institutions should pursue
basic research (not just vocational training). The expansion of
science-based agricultural curricula, the federal funding of sate experiment
stations, and the development of extension services were thus elements in a
linked program of scientific, social, and professional reform. In this
context, manipulative experimental techniques such as hybridization and
crossbreeding served a dual role. They helped define agricultural expertise
in terms of schooled scientific skill rather than day-to-day practice; and
they promoted active intervention to achieve practical goals.

These techniques were central tot he USDA's response to a crisis resulting
from the overproduction of wheat, with the consequent glutting of world
markets and decline in the value of wheat and wheatstuffs. The great
expansion of productivity in American agriculture that created this surplus
preceded by more than a decade the official promotion of hybridization by
the USDA. The purpose of intensive and specialized hybridization work was
therefore not a generalized increase in productivity, which had been
achieved by other means. It was part of a refinement of the system -- a
means to cope with a specific crisis of agricultural production.

The massive increase in U.S. production of wheat in the 1870s, according to
USDA statistician J. R. dodge, was attributable to three factors: the ready
availability of fresh agricultural land; the penetration of the railroads
into areas previously inaccessible to markets; and, most important, an
extraordinarily inflated demand resulting from several years of European
crop failures.[30] The problem, apparent by 1880, had intensified by the
middle of the decade. With the wheat crop of 1884 five times the size of the
1830 crop, and with prices falling in the world market as European
production recovered, the problem of American overproduction began to
concern USDA officials.[31]

In 1885, Dodge suggested a solution ultimately adopted by the department. He
directly linked the overproduction of wheat to the underproduction of other
valuable commodities that the nation now imported.[32] The solution required
that farmers decrease the acreage devoted to wheat production and extend
cultivation to other crops.[33]

With this goal, the USDA developed a three-part corrective program aimed at
diversification of the nation's agricultural products: decreasing the
acreage of wheat in the production; decreasing U.S. reliance on particular
import items; and increasing exports of specialty items of high quality, for
which there was a strong market demand.[34] Generally, this solution
involved an intensification of economic and scientific research, centrally
directed by the USDA, and expert analysis of the general problems of
national agricultural production. In 1887, Commissioner of Agriculture
Norman J. Colman explicitly linked efforts to diversify with the search for
new products.

It is an important question, in view of the rapid increase of available
rural labor, tending to overproduction of the fruits of the soil and the
cheapening of their value, what can be done to give greater variety to the
products of agriculture? What can this Department do towards the
introduction of new plants and development of new rural industries?[35]

In his statistician's report for 1889, Dodge stressed that solving the
problem of overproduction "required the fullest and promptest information
concerning new fruits, fibers, or products of economic plants."[36] Rather
than depressing production, it should be encouraged in new directions,
particularly toward the cultivation of products hitherto imported.[37]
Throughout the 1890s, the secretaries of agriculture echoed these
sentiments; the American farmers should pursue a favorable balance of trade
through the "substitution in our own markets of home-grown for foreign-grown
products."[38]

As diversification, quality improvement, and increased self-sufficiency
became central to the USDA's response, various branches of economic botany
assumed greater importance within the department. Seed introduction, plant
exploration, botany, and horticulture gained in status and acquired new
institutional structures. Botanical specialties such as plant pathology,
pomology, and agrostology achieved independent divisional status for the
first time.[39] Scientists working in these divisions found hybridization
and cross-fertilization valuable for both rhetorical and practical purposes.

In 1885, William M. King, chief of the Seed Division, drew an explicit
connection between crop improvement, hybridization, and reformist
conceptions of social and scientific progress. In pursuit of the division's
purpose, to "promote the interests of all classes, in whatever industrial
pursuits .... by an increased improvement in both quantity and quality of
agricultural products," it should strengthen ties with foreign governments
that would promote the exchange of plants and seeds.[40] King also had
specific ideas concerning the fate of these imports. Hybridization was the
chief means to seed improvement, according to King, and he provided a
two-page summary of hybridization techniques, citing no less an authority
than Charles Darwin in support of the contention that cross-fertilization
was generally beneficial and self-fertilization injurious.[41] His
discussion placed in the fore the improvement of wheat and creation of new
varieties, not surprising given the specter of overproduction and the
importance of grain for the export market. King reproduced a letter from A.
E. Blount, of the State Agricultural College of Colorado, whose
hybridization work in wheat involved "over 300 varieties of seed obtained
from almost every wheat-producing country in the world."[42]

In 1886, the report of H. E. Van Deman of the new Division of Pomology
directly addressed a crucial aspect of the department's diversification
program -- namely, the production of fruits for export. The apple and citrus
fruits were seen a particularly significant; Van Deman's staff was seeking
unusual varieties, both domestic and foreign, of these and other fruits.[43]
The following year, as the acquisition of plants and seeds from foreign
countries continued, the pomologist emphasized the importance of the
"science of breeding" in the creation of artificial hybrids of economic
importance.[44]

Hybridization was thought to apply to "all cultivated plants," thus cutting
across boundaries traditional in agriculture and horticultural research.[45]
This aspect of hybridization was of immense practical and institutional
significance. Numerous specialty divisions of the USDA (as well as other
agricultural research organizations) could offer support. Furthermore, its
universality implied that the technique was based on fundamental natural
laws. Hybridization thus validated agriculture as a biological science, a
feature of special importance to agricultural scientists working in an
academic context. Experiment station researchers and academic reformers
ultimately capitalized on both the technical and institutional implications
of hybridization in their promotion of experimental breeding techniques.

Within the USDA, the laboratories of the Division of Vegetable Pathology
became the locus of hybridization and breeding investigations. Division
chief Beverly T. Galloway insisted on the crucial relationship between
vegetable pathology and vegetable physiology, pointing to the "urgent
necessity of a thorough study of the normal physiology of the plant, as a
groundwork for pathological investigations."[46] Scientific practice within
this conception of the study of plant diseases required "the aid of many
branches of science,"[47] plant breeding among them. Indeed, Galloway argued
that the problems of plant breeding were inseparable from work in plant
pathology and physiology, because the condition of development dictated by
the inheritance of the organism were as crucial to a successful crop as were
the conditions of the environment in which the crop was grown. The goal was
to uncover principles that "will enable the grower to not only modify his
conditions to suit the plants, but to modify the plant to suit the
conditions."[48]

By the close of the century, studies of inheritance in plants and
experimental improvement through breeding and selection were secure elements
in the research of the division, which had been appropriately renamed the
Division of Vegetable Physiology and Pathology. Division researchers had
undertake crossbreeding with grapes, oranges, pineapples, pears, and wheat
and were soon to work with cotton, in all cases seeking to combine excellent
quality of the fruit or grain with hardiness in the face of climatic
severities or with resistance to specific plant diseases. Discussing the
work of the division in 1898, A. F. Woods reported more than 20,000 crosses
of raisin grapes, 116 crosses of pear varieties, the production and
propagation of hundreds of hybrid pineapples, oranges, and other citrus
fruits, and the breeding of wheat for disease resistance and yield.[49]
Several important plant breeders began their professional careers within
this division, including Herbert J. Webber, who would be an important
advocate of Mendelism within agricultural institutions.[50]

During the 1880s and 1890s, then, efforts of USDA administrators and
scientists to generate new products promoted hybridization and varietal
crossing. The cultivation of specialty items to replace some imports and
provide new products for export was central to their program of economic
reform. Moreover, the use of hybridization, presented as a technique
demanding specialized skills, also played an important role in scientific
reform, which penetrated not only the USDA but the nation's agricultural
colleges and experiment stations.

Research and Reform: The Place of Hybridization

By the 1880s, USDA officials had developed a strong research orientation.
The scientific work conducted under their auspices was accompanied by a
marked appreciation for the power of science.[51] At the same time, with
passage of the Hatch act ensuring that agricultural experimentation would
receive significant public support, USDA administrators were determined to
exert more control over the state experiment stations.[52] The scientific
research ethos permeating the department inevitably played a role in
management of the stations, as shown by the annual reports filed by the
secretary of agriculture. Each year the secretary complained that farmers
and state legislators who demanded practical help misunderstood the purpose
of the experiment stations, whose mission was original investigation. James
Wilson's report for 1898 is typical. After noting that experiment stations
were not the only means for educating the farmer (who could make use of
agricultural colleges, farmers' institutes, and boards of agriculture), he
argued:

     It is the business of the experiment station, on the other hand,
     to advance knowledge of the fact and principles underlying
     successful agriculture and to teach the farmer new truths made
     known by their investigations. The act of Congress creating the
     Stations clearly defines their functions to be the making and
     publishing of original investigations. Whenever a station has
     neglected this and merely endeavored to educate the farmer, we
     find a weak station, and whenever a station has earnestly devoted
     itself to original investigations, we find a strong station.[53]

The Office of Experiment Stations (OES) was created by the commissioner of
agriculture, under the authority of the Hatch Act, to oversee the work of
the stations and provide a central clearinghouse for station research.[54]
Its commitment to station research increased under Alfred C. True, who
became director in 1893.[55] At the same time, a number of botanists and
horticulturalists at the agricultural colleges and stations, some with
training or research experience at elite American and European institutions,
were happy to comply. In fact, they had pioneered experimental work at their
home institutions and introduced it in their teaching.[56] Plant breeding,
already recognized as an important experimental technique with agricultural
applications, assumed its place in the armamentarium of reform. Scientific
reformers like True, endeavoring to achieve their goals while maintaining a
commitment to practical applications, promoted breeding work as part of the
movement to transform the agricultural experiment stations into
scientifically oriented research centers.

The leadership of the OES at this time was important because, despite the
enthusiasm of like-minded investigators at some institutions, horticultural
work at most stations consisted chiefly of variety testing, some plant
pathology, and experimentation with culture methods.[57] The horticultural
work of many stations was weakly developed, and in 1889 four stations
specified that no varietal improvement would be attempted in vegetable
crops.[58] But the same economic forces that prompted the development of the
USDA's diversification and crop improvement program operated in the states
with even greater immediacy, and in the years following the passage of the
Hatch Act, many stations adopted programs of variety improvement, to proceed
chiefly by selection techniques. By 1889, twenty-three stations reported
active or planned programs of variety improvement, and eight specified
hybridization would be part of these efforts.[59]

True and his staff were not content merely to document a growing interest in
hybridization. In 1890, the OES published results of a questionnaire that it
had presented to the stations, probing the nature and extent of botanical
work by station researchers. Most questions pertained exclusively to applied
research. Two questions, however, specified research areas with no explicit
mention of practical applications. One concerned plant physiology. The other
asked pointedly: "Are you experimenting in cross-fertilization and
hybridization in the hope of obtaining better knowledge of the laws that
underlie these processes?"[60]

The research areas singled out were unambiguously stamped with OES approval,
and the questionnaire therefore served a propagandistic, as well as
informational, purpose. The responses from station botanists reveal that
they were prepared to be encouraged. Of thirty-eight stations responding,
twenty indicated that they were already engaged in cross-fertilization and
hybridization work. Seven of the twenty specified that their work in this
area was limited, but six indicated that crossbreeding work was expected to
be a major aspect, in some cases a specialty, of their research. Three
others that had not yet begun such work reported plans to initiate it in the
near future.[61]

As important as the actual extent of hybridization work is the evidence of
growing interest in the subject among station researchers. Since the 1888
station reports to the OES, the number of institutions undertaking crop
improvement through hybridization as well as selection had increased from
seven to twenty. The particular economic pressures within the various states
ensured the application of the technique to virtually all horticultural and
field crops. At the Florida station, investigators hybridized peaches and
oranges; at Arkansas, strawberries; at Michigan, wheat; at Massachusetts and
Indiana, fruit tress; and at Iowa, corn. Other stations quickly followed
suit.[62]

Significantly, this late nineteenth-century work in hybridization and
crossbreeding was undertaken by personnel at publicly supported research and
teaching institutions, unlike such work earlier in the century, which was
pursued chiefly by private individuals or commercial concerns. The public
institutions, numerous and geographically dispersed, were charged with
education and technical training: researchers, and more importantly
students, gained experience in growing, propagating, manipulating, and
hybridizing plant materials -- skills crucial for research in plant
inheritance. The public institutions thus provided a new context for
hybridization studies, a formally structured academic context, where workers
undertook research beneath a standard proclaiming commitment to science as
the basis for practical advancement. Although improved varieties of
agricultural crops were undoubtedly the ultimate goal of the USDA or
station-sponsored work, the wording of the OES's 1890 questionnaire
explicitly presented the aim of such work as "better knowledge of the laws
that underlie the processes." At the stations, as at the USDA, the
significance and institutional success of crossbreeding lay in its dual
implications for practical applications and scientific theory. The technique
was particularly appropriate for the agricultural institutions, struggling
to combine their economic and social service role with allegiance to the
values of academic science.

The rediscovery of Mendel's work in 1900 thus occurred at a time when
hybridization was of unprecedented importance in American agricultural
research. The scientific reform of agricultural research and education
ensured that many breeders would be college professors or college-trained
researchers. For these men, breeding work had a scientific goal, the
investigation of universal laws of inheritance, as well as a practical one.
Station investigators were thus sensitive to problems uniting intellectual
and commercial concerns -- and hence particularly concerned with the nature
of variation -- before 1900. Station botanists sought to understand the
relationship between certain types of crosses and the appearance of
sterility in offspring, a results obviously to be avoided in efforts to
produce self-sustaining lines of improved varieties. Several researchers
studied the influence of crossbreeding and hybridization on the expressions
of heritable characteristics in search of regularities in their
transmission.[63] Workers with corn at the Illinois stations considered
commercial features such a as size of the ear as well patterns in the
inheritance of kernel color, and then examined the greater or lesser
stability (or constancy) of hybrid effects in subsequent generations.[64] In
short, at many of the agricultural experiment stations researchers were
engaged in the study of variation -- its appearance, alteration, and
constancy through several generations.

Mendel, Bateson, and American Agriculturalists

In this same period, variation also assumed a central place in biological
investigations. Darwinian evolutionary theory, whether accepted or rejected,
defined the problems of biological research in the second half of the
nineteenth century. Chief among the serious objections to Darwin's theory
were perceived inadequacies in his treatment of the origin and transmission
of variation. For scientists concerned with evolutionary issues, the
production of new varieties through cross-fertilization and hybridization
represented a valuable experimental method for investigating these problems.
William Bateson published his Materials for the Study of Variation in 1894,
providing scientists with a handbook of "experimental evolution," and Hugo
de Vries's concern with establishing a truly experimental study of evolution
prompted his search for both hybrid constancy and spontaneous appearances of
saltatory variation.[65]

The conjunction of research interest among students of evolutionary theory
and practical breeders proved crucial for the rapid success of Mendelism in
the United States. The 1899 Conference on Hybridization and Cross-breeding,
convened in London by the Royal Horticultural Society, brought these groups
together. In attendance were British, American, and continental scientists
with wide-ranging theoretical, practical, and commercial interests in
botanical hybrids.

The participants included William Bateson, Hugo de Vries, and C. C. Hurst.
Also present, by invitation, were American agricultural scientists Herbert
J. Webber, David Fairchild, and Walter Swingle of the USDA and Willet M.
Hays of the Minnesota experiment station. Liberty Hyde Bailey, also invited
but unable to attend, sent a paper.[66] The conference proceedings reveal
that theoretical investigators, practical agriculturalists, and commercial
breeders had common interests in hybridization.

William Bateson was a masterful presence; his conference paper, focusing on
transmission of discrete characters in hybrid crosses between closely
related individual, emphasized the value of experimental hybridization for
evolutionary theory. He also discussed the problem of swamping, raised
regularly in critiques of Darwinism.[67] De Vries explained his most recent
breeding experiments, interpreting the creation of apparently stable hybrid
crosses as a possibly crucial mechanism for evolution.[68] Hurst discussed
his cross-breeding experiments at length, and elaborated a law of "partial
prepotency."[69] While both Bateson and de Vries addressed problems of
concern to practical investigators, Hurst was the most thorough and explicit
in linking the work of practical breeders and students of evolution. He
insisted that the results of crossbreeding experiments seemed "bear directly
upon the problems of inheritance and variation," and pointed to the problem
of hybrid constancy as central to breeding practice.[70] he thus provided a
powerful justification for pursuing basic research on hybridity as the basis
for further practical achievements.

The Americans spoke and wrote almost exclusively of practical advances in
plant breeding in the United States. Thus Webber lauded the successes of the
USDA's hybridization work in oranges, pineapples, pears, apples, wheat,
corn, and cotton.[71] Hays's contribution indicates that, in general, the
American focus was on broad characteristics of economic significance, such
as vigor, hardiness, and size.[72] But despite some differences in
orientation, the American agricultural scientists were obviously excited by
the spirit of scientific cooperation, and seemed impressed by the British
and European studies. They also made a strong impression on their British
audience, some of who expressed envy of the institutional support available
for hybridization work in the United States.[73]

Between the 1899 conference in London and the 1902 conference in New York,
Mendel's work had been rediscovered, and Bateson had embarked on a campaign
to promote it. Because American agriculturists were already familiar with
Bateson's views and because the American agricultural research apparatus was
attuned to relevant issues. Bateson's success at the 1902 conference is
understandable. The editorialist for the Experiment Station Record crowed
that "there was an almost universal acceptance of Mendel's law regarding the
appearance of dominant and recessive hybrids,"[74] Although not every
participant was persuaded either of the generality of Mendel's laws or their
practical importance, the enthusiasm was widespread -- among seedsmen as
well as scientists. We have tried to explain Mendel's appeal to agricultural
scientists. But what was his appeal to seedsmen?

Marketing Mendel

The answer is partly that Mendelism offered a plausible explanation for the
extreme difficulty in obtaining varieties that would "breed true." Specific
results that had long puzzled practical breeders included the "reversions on
crossing" discussed by Darwin, the greater variability of new types, and the
problem of fixing hybrids. It was doubtless interesting to know why some
varieties could apparently not be fixed, despite repeated selection, and why
success was so long in coming with others. However, these breeders were also
practical, interested in knowledge as a means to power, and power as a means
to profit, not as an end in itself. The laws of heredity were sold to
breeders as a set of rules for efficient selection, worth "a total of
hundreds of millions of dollars' worth of added annual income with but
little added expenditure."[75] The laws of dominance and segregation were
unabashedly advertised as a means to make money; Spillman could assert that
"if Mendel's law is true, it is worth millions of dollars to the breeders of
plants in this country."[76]

Among the scientists, only Liberty Hyde Bailey was publicly doubtful. "The
wildest prophecies have been made in respect to the application of Mendel's
law to the practice of plant breeding," he wrote in 1903.[77] Bailey's
caution reflected his doubt about the generality of Mendel's results. But it
also reflected his realization that even if Mendel's laws were both true and
universal, they would have no immediate dramatic effect on the practice of
plant breeding. Before Mendel, breeders selected; after Mendel, they would
do the same. They might be moved to keep better records, select individuals,
and select from a larger number of plants. The main difference, however, was
that they could now provide plausible explanations for their successes and
failures. They would learn that the "rogue characters" they each year hoed
out resulted from "the fortuitous union of recessive germs."[78] But they
could not eliminate these rogues except by the methods they always used.
Their traditional maxims had been: "Avoid breeding for antagonistic
characters," Breed for on thing at a time," "Know what you want," "Have a
definite ideal," and "Keep the variety up to standard."[79] They now knew
that these maxims made sense. But Mendelism did not, could not (indeed,
cannot) offer a fixed rule by which to "produce six inch carnations on four
foot stems." It could not, at this point, do much for commercial breeders at
all. That situation would change dramatically with two linked developments:
a Mendelian interpretation of the effects of inbreeding (and crossbreeding)
and invention of the double-cross method of breeding -- work that made
possible the development of hybrid corn.

The Invention of Hybrid Corn

Hybrid corn has been repeatedly characterized as "the greatest success story
of genetics."[80] The belief that hybrids are responsible for vast increases
in yield has, however, recently been challenged by Jean-Pierre Berlan and
Richard Lewontin.[81] In their view, the story of hybrid corn illustrates
the success of seed companies, not science. Traditionally, farmers harvested
their next year's seed from their own plants. But one cannot use seed
obtained from hybrids without suffering substantial declines in yield. Thus
farmers must buy their seed anew each year. This feature of hybrids -- and
not any intrinsic superiority in respect to yield, disease resistance, or
other important traits -- explains seed companies' huge investment in their
development. Conventional comparisons of hybrids with open-pollinated
varieties are therefore beside the point. Hybrids, of course, do better.
They have been intensively improved for the last sixty years. Had mass
selection of open-pollinates been pursued with equal zeal, they should now
out-perform hybrids.[82] But seed companies have no incentive to improve a
product that anyone can reproduce.

However, hybrid corn was initially developed by scientists, not seedsmen.
Why should they have cared if breeders were commercially successful? To
answer this question, it is necessary to sketch briefly some developments in
maize genetics between 1905 and 1919.

Hybrid corn developed out of the work of three geneticists: George H. Shull,
then at the Carnegie Station at Cold Spring Harbor, Edward M. East, then at
the Connecticut Agricultural Experiment Station, and East's student, Donald
F. Jones, also at Connecticut. East and Shull were particularly concerned
with the analysis of quantitative characters. All worked with corn, an ideal
subject for such study. Naturally open-pollinated, each kernel may be
fertilized with pollen from a different plant. In a single ear of corn,
therefore, the researcher can obtain a large and highly variable population.
Moreover, the variability is reflected in such easily measurable
characteristics as the size, shape, number, and color of different kernels.
It was also a crop of great, and steadily increasing economic importance.
Between 1866 and 1900 the total corn acreage tripled while production
quadrupled; by the turn of the century, twice as much corn was produced as
wheat, the second most valuable crop.

Thus theoretical and practical interests combined, in the early years of
American genetics, to focus attention on corn. The careers of East and Shull
nicely illustrate this point. East began as a chemist at Illinois, working
with C. G. Hopkins to develop strains of corn with high oil and low protein,
and low oil and high protein content (to improve its value as livestock
feed). In 1905, he began experiments to examine the effects of inbreeding,
work he expanded after moving to Connecticut later that year. Shull, on the
other hand, initially used corn to test a criticism of de Vries's Oenothera
studies (that his mutations were artifacts of selfing a species that was
naturally cross-fertilizing). This work spurred an interest in testing the
effects of selfing and crossing on the expression of a purely quantitative
character.[83] Because it was such an easy trait to measure, Shull chose the
number of kernel rows in an ear of corn.

Using hand pollination, Shull inbred a number of lines (thereby reducing
their variability). As inbreeding progressed, the plants declined in respect
to such desirable traits as size and strength of the stalks, number of ears,
and resistance to disease; the decline in "vigor" corresponded with the
increase in homozygosity and ultimately leveled off.[84] Shull assumed that
his inbreeding had resulted in the isolation of "pure lines" or "biotypes"
similar to those described by Wilhelm Johannsen in beans. When he then
crossed these lines, the offspring were not only superior to their parents
in size and general vigor; they sometimes surpassed the original
open-pollinated corn plants. (Working independently, East had observed
similar effects in inbreeding and crossing, but did not connect them to
Johannsen's pure lines.)

East and Shull were hardly the first to note that deterioration often
accompanies inbreeding, and an increase in general luxuriance or vigor the
crossing of closely related strains. However, the cause of "inbreeding
depression" remained obscure, as did its relation to hybrid vigor. The
former was generally assumed to result from an accumulation of injurious
individual variations, which in turn produced "unbalanced constitutions."
Inbreeding was thus viewed as a process of continual degeneration.[85] Shull
argued that deterioration did not result from self-fertilization per se. In
his view, it was an indirect effect of the isolation of distinct biotypes
(or pure lines). Hybrid vigor resulted from their mixture, and was therefore
simply the converse of inbreeding depression.

Shull also recognized that it was almost impossible for a corn plant to
self-fertilize, given the lightness of the pollen shed by the male flowers
and the location of the female flowers halfway down the stem. He therefore
concluded that virtually every plant in a field of corn is naturally a
hybrid -- although one resulting from a "promiscuous" process of
fertilization. To exploit fully the benefits of hybrid vigor, he proposed to
substitute a process that was completely controlled. His "pure line method
of corn breeding" would maintain otherwise useless lines of corn solely for
the purpose of utilizing the vigor obtained from their crossing. Shull
argued that a policy of simple selection for the best individuals would not
be effective, because the value of the resulting strains differed not only
in their pure state but also in their various hybrid combinations. Ordinary
methods of selection could take only the former into account. However, it
was not possible to predict the relative vigor of hybrids simply from the
value of the pure lines that produced them. "The object of the corn breeder"
Shull wrote, "should not be to find the best pureline, but to find and
maintain the best hybrid combination."[86] But the technique he suggested
produced seed corn too expensive for commercial use.

The ultimate source of hybrid vigor is moreover as obscure in Shull's
account as it was in pre-Mendelian works, such as Darwin's.[87] According to
Shull, vigor results from crossing because crossing greatly increases the
mixture of biotypes in the new hybrid strains. But why should mixing
biotypes be beneficial? On this point, Shull is silent. In early 1909
however, he read a paper by East, also opposing the view that inbreeding per
se was deleterious, in which East did advance an explanation of inbreeding
depression and hybrid vigor.[88] More accurately, he proposed two.

Following Davenport, East first considered a simple Mendelian account of the
effects of inbreeding -- that it uncovers deleterious recessives (whose
effects are masked by crossing). However, he believed this hypothesis
inadequate for it failed to account for both developmental and genetic
effects. East assumed that sexual reproduction has two functions: to
recombine hereditary characters and to stimulate development. He suggested
that this beneficial stimulation would be increased by the crossing of " two
strains differing in gametic structure."[89] (That fertilization serves to
"rejuvenate the egg" as well as create new genetic combinations was then a
common belief.[90]) Hybrid vigor is thus largely attributable to "the
physiological stimulation of heterozygosis," a phrase that Shull shortened
to "heterosis" in 1914.[91]

From this standpoint, hybrid vigor results from the beneficial effects of
hybridity per se. "In other words, " Shull wrote, "hybridity itself, -- the
union of unlike elements, the state of being heterozygous, -- has, according
to my view, a stimulating effect upon the physiological activities of the
organism."[92] As a corollary, it was not possible to produce pure lines as
productive as hybrids; and because the quality of hybrids deteriorates after
the first generation, the only way to obtain maximum yields was to return
each year to the original combination.[93] Farmers could not effectively
reuse their seed. "Like the mule, CROSSED CORN has the advantage of hybrid
vigor," asserted an early advertisement; like the mule, it is also
effectively sterile. As Shull approvingly noted: "When the farmer wants to
duplicate the splendid results he has had one year with hybrid corn, his
only recourse is to return to the same hybridizer from whom he secured his
seed the previous year and obtain again the same hybrid combination."[94] If
vigor is a function of the degree of heterozygosis, hybrids are grounded in
an unfortunate (from the farmers' perspective) fact of nature. However, the
view that heterozygotes were inherently superior had become a minority
position long before the commercial development of hybrids. From the
beginning, it had a rival -- a truly Mendelian interpretation of inbreeding.
Even in the nineteenth century, a few breeders held that in crosses parents
usually possess different defects that tend to cancel out in their
progeny.[95] After 1900, this insight was easily rephrased in Mendelian
terms -- that is, in the course of selection for various traits, breeders
create strains that are homozygous for deleterious genes elsewhere in the
genome. A hybrid formed between two inbred strains would acquire normal,
dominant alleles at most of these loci.

The dominance interpretation of hybrid vigor was not immediately compelling
because it predicted results that did not completely according with
observation (such as a skew distribution in the second generation). These
anomalies disappeared, however, when linkage or the involvement of at least
twenty genes was assumed. Moreover, the concept of physiological stimulation
arising in some unknown way from heterozygosity was both distressingly vague
and unsupported by any evidence.[96] Even East was later to admit that it
was "an assumption for which there was no proof, and which was not
illuminating as a dynamic interpretation."[97]

By 1919, when East and his student Jones published their influential book
Inbreeding and Outbreeding, the "heterosis concept" was already in
retreat.[98] (Jones invented the double-cross method of breeding, which made
the production of hybrid seed commercially viable.[99]) They themselves
concluded that the dominance interpretation of hybrid vigor was correct --
hence, that pure lines were in theory more desirable than hybrids.[100]

In the 1920s and 1930s, the dominance explanation was generally accepted. In
the 1940s, it would be challenged by Fred Hull, who argued that intrinsic
heterozygote superiority (which he termed "overdominance") provided a
partial explanation of hybrid vigor in corn.[101] This view was popularized
by Jay Lush, author of the leading text on animal breeding.[102] Thus the
East/Shull thesis of vigor resulting from the physiological stimulation
produced by unlike gametes would eventually reappear in new, Mendelian garb.
By then, however, virtually the entire corn belt had been planted in
hybrids.[103] If the dominance explanation was widely accepted in the 1930s,
how were hybrids justified? In part, as an expedient.

East and Jones believed that mass selection of open-pollinated varieties
would ultimately produced lines as good or better than hybrids. In
Inbreeding and Outbreeding, the success of the dominance interpretation of
hybrid vigor is characterized as a "happy result." Why? Because the
physiological stimulation hypothesis "locked the door on any hope of
originating pure strains having as much vigor as first generation
hybrids."[104] Hybrids produced a uniform field and (under some
circumstances) a rapid boost in yield.[105] But selection could ultimately
do the same and more. For East and Jones understood that dominance was
rarely complete. "Perfect dominance, except in more or less superficial
characters, rarely occurs, and even when it does occur, it may be merely an
appearance rather than a reality," they wrote. The consensus was "that there
is no such thing as perfect dominance, that the heterozygote merely
approaches the condition of one or the other parent more closely."[106]

The conclusion is obvious. If dominant genes do not completely mask the
effects of deleterious recessives, selection should eventually produce pure
lines superior to hybrids. In their words: "if dominance is but partial,
this [homozygous] individual, through the very fact of its homozygous
condition, will be even more vigorous that those of the first hybrid
generation."[107] Thus, they predicted that hybrids would ultimately be
replaced by pure lines.[108] Yet when they considered the mechanics of plant
and animal improvement, the only method described was hybridization, and
hybrids, in fact, remained the only approach to improvement of corn. By the
1930s, mass selection of open-pollinated varieties was no longer discussed.

East and Jones also provide a clue to the reason why. After explaining that
Jones' double-cross method might appear complex, they write:

     It is not a method that will interest most farmers, but it is
     something that may easily be taken up by seedsmen; in fact, it is
     the first time in agricultural history that a seedsman is enabled
     to gain the full benefit from a desirable origination of his own
     or something that he has purchased. The man who originates devices
     to open our boxes of shoe polish or to autograph our camera
     negatives, is able to patent his product and gain the full reward
     of his inventiveness. The man who originates a new plant which may
     be of incalculable benefit to the whole country gets nothing --
     not even fame -- for his pains, as the plants can be propagated by
     anyone. There is correspondingly less incentive for the production
     of improved types. The utilization of first generation hybrids
     enables the originator to keep the parental types and give out
     only the crossed seeds, which are less valuable for continued
     propagation.[109]

East and Jones believed that commercial breeders would not have sufficient
incentive to improve plants until they could prevent farmers from using
their own crops to propagate the next generation. Hybrids in effect
conferred the equivalent of a patent right on new varieties of seed. East
and Jones knew that, in theory, hybrids were not the only, or even the best
route, to improvement of corn. They themselves identified the alternative.
But that method, as a breeder associated with Jones wrote, would probably
"spoil the prospects of any one thinking of producing the seed
commercially."[110] Without the commercial incentive provided by hybrids,
they believed that corn would not be improved. With the breeders, East and
Jones also thought it fundamentally unjust that the creators of new plants
and animals should fail to profit by their inventions.[111]

They thus faced a dilemma. East and Jones held a scientific theory according
to which pure lines should produce maximum increases in yield. But they also
held a social theory (reflecting the facts of their actual world), according
to which improvement of corn required an incentive for commercial producers
that only hybrids could offer. Their prediction that pure lines would one
day replace hybrids was therefore naive. Who would improve the
open-pollinated varieties? They answer might seem obvious: state
universities and their affiliated experiment stations. After all, a
commitment to the welfare of the farmer and the general public was at the
heart of the experiment station ideology. However, public institutions
proved unable to resist the clamor for hybrids, on the part of both farmers
(excited by seed company advertising and focused on short-term gains) and
large seed producers (whose representatives dominated university crop
advisory committees).[112] Thus the interests of those who aimed to make
seed a commodity ultimately prevailed over those who opposed it. But that is
another story.[113]

Conclusion

The development of hybrid corn was no simple matter of the transfer of
theoretical science from an elite academic to an applied commercial context.
Much of the theoretical work that made hybrids possible was pursued at
institutions concerned with improving the efficiency and productivity of
agriculture. In the 1880s, agricultural administrators began to promote
hybridization as part of an effort to produce commercially viable new
varieties. Ongoing interest in hybridization, in turn, underlay an
enthusiastic response to Mendelism among researchers at the USDA and at
agricultural colleges and experiment stations. However, agricultural leaders
and researchers were also committed to basic research and scientific reform.
The agricultural disciplines and institutions were themselves flourishing
hybrids.

Mendelism between 1900 and 1910 was thus an applied science, in the literal
sense of both; it was surely applied, and it was certainly science. The
rapid development of genetics within an agricultural context, where
breeding, selection techniques, hybridization, and even evolutionary issues
had been addressed in the late nineteenth century, endowed Mendelism in the
United States with a strongly practical and popular aspect. It also ensured
that fundamental problems in genetics would be addressed within institutions
oriented to practical ends -- and that the subsequent development of genetic
research would often reflect dominant social and economic interests in
American agriculture.

The case study of hybrid corn illustrates these points. George Shull was not
trained at an agricultural institution nor did he ever work at one; but his
early experience of Mendelism brought him close to horticultural and
agricultural researchers and to involvement with practical issues. Edward
East was trained and did his early work at agricultural colleges and
experiment stations before moving to Harvard's Bussey Institution, and
Donald Jones worked at the Connecticut station throughout his career. That
their research ultimately provided an important breakthrough for commercial
agriculture is comprehensible within the complex constraints and
constituencies of the scientists' sponsoring institutions.

Numerous centennial and celebratory volumes document the achievements of the
USDA, state experiment stations, and agricultural colleges. However, these
institutions have generally been given short shrift by historians of
biology. Their attention has focused on the elite college and laboratories
dedicated to the idea of pure research.

From the perspective of researchers at Johns Hopkins, Columbia, or Woods
Hole, agricultural colleges and experiment stations were doubtless at the
periphery of the new biology. However, we see no reason to privilege their
standpoint. It certainly does not accord with the self-conception of those
employed at agricultural institutions. They were generally proud of their
mandate: to serve the public interest. As we have seen, that goal did not
exclude a commitment to basic research. On the contrary, much fundamental
work in biology, especially genetics, emerged from these institutions. For
this reason alone, they deserve greater attention from historians of
biology. Of further interest is the fact that their research agendas
reflected, in a particularly blunt way, political and economic interests. To
consider these institutions is thus to broaden our understanding both of
American culture and American science.

Acknowledgments

We would like to thank several individuals. Barbara Kimmelman gratefully
ackknowledges the support of her doctoral advisor, Robert Kohler. Diane Paul
is indebted to Richard Lewontin and to two other visitors in his population
genetics laboratory during 1986-87. Michel Veuille persisted in asking
questions about the American receptions of Mendelism that inspired this
research. The case study that concludes this essay draws heavily on work,
some of it unpublished, by Jean-Pierre Berlan and Lewontin. We are also
grateful to Deborah Fitzgerald for sharing her research on the development
of hybrid corn in Illinois and for many helpful comments on successive
drafts of this essay.


Notes:

1 Willet M. Hays, "Address by Chairman of Organization Committee,"
Proceedings of the American Breeders Association, 1905, 1: 9-15.

2 William Bateson, "Hybridisation and Cross-breeding as a Method of
Scientific Investigation," Journal of the Royal Horticultural Society, 1900,
24: 59-66.

3 Charles Davenport, "Report of the Committee on Eugenics," The American
Breeders Magazine, 1910, 1: 126-129. See also Barbara A. Kimmelman, "The
American Breeders Association: Genetics and Eugenics in an Agricultural
Context," Social Studies of Science, 1983, 13: 163-204.

4 Deborah K. Fitzgerald, "The Business of Breeding: Public and Private
Development of Hybrid Corn in Illinois, 1890-1940" (Ph.D. dissertations,
University of Pennsylvania, 1985).

5 During this period, investigators generally used the terms hybridization,
crossbreeding, and cross-fertlization to mean, respectively, interspecific
crosses, intervarietal crosses, and intraspecific crosses between male and
female of different plants. Darwin based his crucial analogy between
interspecific hybrids and intervarietal mongrels on such distinctions. In
practice, the analogy proved more powerful than the distinction, and many
investigators used the terms interchangeably. We will see that, after 1910,
hybrids came to acquire a more precise, technical meaning.

6 Walter A. Cannon, "Review of Proceedings: International Conference on
Plant Breeding and Hybridization," Torreya, 1905, 1: 12-14.

7 C. W. Ward, "Improvement of Carnations," Memoirs of the Horticultural
Society of New York, 1904, 1: 151-155.

8 William Bateson, "Practical Aspects of the New Discoveries in Heredity,"
Mems. Hort. Soc. N.Y., 1904, 1: 1-8.

9 William Bateson, Mendel's Principles of Heredity: A Defence (Cambridge:
Cambridge University Press; New York: MacMillan Co.; 1902) Alan Cock notes
that the book was published on 3 or 4 June 1902 in Britain and must have
appeared almost simultaneously in the United States (private communication).

10 Liberty Hyde Bailey, "Comments," Mems. Hort. Soc. N.Y., 1904, 1: 8.

11 William Bateson to Beatrice Bateson, 3 October 1902, William Bateson
papers, University of Cambridge Library, letter G-3D-05; typed transcript at
G8G01D. We gratefully acknowledge the Library's permission to quote the
Bateson letter. The originals of the collection prefaced G have recently
been transferred to the Library from the John Innes Institute, which now has
photocopies. Mrs. Rosemary Harvey, archivist at the John Innes, kindly
supplied copies of Bateson's 1902 letters from America.

12 Garland Allen, Life Science in the Twentieth Century (New York: John
Wiley and Sons, 1975), p. 52.

13 Ibid.

14 "Seedsmen," or "practical breeders," were primarily farmers who also bred
particular varieties of seed/grain for purpose of sale. A few of these
farmers (such as the Funks) engaged in breeding for sale as a major
enterprise but for most it was a minor activity. Some seedsmen (mostly urban
horticulturalists) were businessmen simpliciter.

15 Barbara A. Kimmelman examines the founding and early years of research
departments in genetics within the agricultural colleges at Ithaca, N.Y.,
Madison, Wis., and Berkeley, Calif., in "A Progressive Era Discipline:
Genetics at American Agricultural Colleges and Experiment Stations,
1890-1920," (Ph.D. dissertations, University of Pennsylvania, 1987).

16 Bateson, "Practical Aspects," p. 3.

17 C. C. Hurst, "Notes on Mendel's Methods of Cross Breeding," Mems. Hort.
Soc. N.Y., 1904, 1: 11-16. Hugo de Vries, "On Artificial Atavism," Mems.
Hort. Soc. N.Y., 1904, 1: 16-23.

18 This point is illustrated by the diverse character of articles on
Mendelism published in American journals between 1901 and 1903. The first to
appear was Charles Davenport's "Mendel's Laws of Dichotomy," in the
Biological Bulletin, 1901, 2: 307-310. It was quickly followed by E. B.
Wilson, "Mendel's Principles of Heredity and the Maturation of the
Germ-cells," Science, 1902, 16: 991-992; Walter Sutton, "On the Morphology
of the Chromosome Group in Brachystola magna," Biol. Bull., 1902, 3: 24-39;
W. J. Spillman, "Exceptions to Mendel's Law," Sci., 1902, 16: 709-710 and
784-796; R. A. Emerson, "Preliminary Account of Variation in Bean Hybrids,"
15th Annual Report of the Nebraska Experiment Station, 1902; and Walter A.
Cannon, "A Cytological Basis for Mendelian Cases," Bulletin of the Torrey
Botanical Club, 1902. Other early accounts include Liberty Hyde Bailey, "A
Discussion of Mendel's Law and its Bearings," Address before the Society for
Plant Morphology and Physiology, Washington, D. C., 29 Dec. 1902, published
as "Some Recent Ideas on the Evolution of Plants," Sci., 1903, 17: 441-454;
Walter Sutton, "The Chromosomes in Heredity," Biol. Bull., 1902, 4: 231-251;
and William Castle, "The Laws of Heredity of Galton and Mendel and some Laws
Governing Race Improvement by Selection," Proceedings of the American
Academy of Arts and Sciences, 1903, 38: 535-548; reprinted as "Mendel's Law
of Heredity," in Sci., 1903, 18: 396-406. Compare with the lack of interest
expressed by the Botanical Gazette. The first mention of Mendel is a
dismissive comment by the editor, John Merle Coulter, in a review of the
third edition of Liberty Hyde Bailey's Plant Breeding (Botanical Gazette,
1904, 37: 471-472). The American Naturalist was also unimpressed. Other than
a passing reference in a Botanical Note of 1902, there is no mention of
Mendelism until 1904, and then only in Charles Davenport's book reviews.
Editorial notes and articles first appear in 1907.

19 Jan Sapp, "The Struggle for Authority in the Field of Heredity,
1900-1932: New Perspectives on the Rise of Genetics," Journal of the History
of Biology, 1983, 16: 311-342.

20 Willet M. Hays, "Address by Chairman of Organization Committee," p. 10.

21 W. J. Spillman, "Mendel's Law in Relation to Animal Breeding," Proc. ABA,
1905, 1: 171-176; H. J. Webber, "Explanation of Mendel's Law of Hybrids,"
Proc. ABA, 1905, 1: 138-143.

22 William Bateson, "G. Mendel: Experiments in Plant Hybridisation," J.
Royal Hort. Soc., 1901, 26: 1-32.

23 U.S. Department of Agriculture, Office of Experiment Stations, Abstract
of G. Mendel, "Experiments in Plant Hybridization," Experiment Station
Record, 1901-1902, vol. 13 (Washington, D. C. : Government Printing Office,
1902), p. 744.

24 Ibid., p. 745.

25 Ibid., p. 1004.

26 See, for example, U. S. Department of Agriculture, Office of Experiment
Stations, Abstracts of W. F. R. Weldon, "Mendel's Law of Alternative
Inheritance in Peas," C. C. Hurst, "Mendel's Law Applied to Orchid Hybrids,"
and Carl Correns, "Apparent Exceptions to Mendel's Law of Dissociation in
Hybrids," Experiment Station Record, 1902-1903, vol. 14 (Washington, D. C. :
Government Printing Office, 1903), pp. 466-467, 569. Also see U. S.
Department of Agriculture, Office of Experiment Stations, Abstracts of A. D.
Darbishire, "On the Bearing of Mendelian Principles of Heredity on Current
Theories of the Origin of Species," Erich von Tschermak, "Further Studies in
Crossing Peas, Stocks and Beans," and David Starr Jordan, "Some Experiments
of Luther Burbank," Experiment Station Record, 1904-1905, vol. 16
(Washington, D. C. : Government Printing Office, 1905), pp. 232, 263,
773-774. Jordan's study indicated that Burbank's results did not generally
conform to Mendel's laws.

27 Bailey, "A Discussion of Mendel's Law," pp. 445-446.

28 Margaret Rossiter, "The Organization of the Agricultural Sciences," in
Alexandra Oleson and John Voss, eds., The Organization of Knowledge in
Modern America, 1860-1920 (Baltimore: Johns Hopkins University Press, 1979),
pp. 211-248.

29 Our interpretation of the Progressive Era accords with the work of Sidney
Fine, Laissez Faire and the General Welfare State: A Study of Conflict in
American Thought 1865-1901 (Ann Arbor: University of Michigan Press, 1956);
Samuel P. Hays, The Response to Industrialism 1885-1914 (Chicago: University
of Chicago Press, 1947); Harold U. Faulkner, Politics, Reform, and Expansion
1890-1900 (New York: Harper and Row, 1959); Robert H. Weibe, The Search for
Order 1877-1920 (New York: Hill and Wang, 1967); and James Weinstein, The
Corporate Ideal in the Liberal State 1890-1918 (Boston: Beacon Press, 1968).
See also Samuel P. Hays, "Introduction: The New Organizational Society," in
Jerry Israel, ed. Building the Organizational Society (New York: The Free
Press, 1972), pp. 1-15.

30 U. S. Department of Agriculture, Report to the Commissioner of
Agriculture for the year 1885 "Report of the Statistician," by J. R. Dodge
(Washington, D. C.: Government Printing Office, 1885), p. 372.

31 For example, see U. S. Department of Agriculture, Report to the
Commissioner of Agriculture for the year 1880, "Report of the Statistician,"
by Charles Worthington (Washington, D. C.: Government Printing Office,
1880), p. 210; Dodge, "Report of the Statistician," pp. 372-376; and U. S.
Department of Agriculture, First Report of the Secretary of Agriculture,
1889, "Report of the Secretary of Agriculture," by J. M. Rusk (Washington,
D. C.: Government Printing Office, 1889), p. 14.

32 Dodge, "Report of the Statistician," pp. 379-380.

33 Ibid., p. 373.

34 A valuable discussion of the growing importance of U. S. international
markets (although, like its subjects, it disparages the significance of the
agricultural sector) is Walter LeFeber, The New Empire: An Interpretation of
American Expansion 1860-1898 (Ithaca: Cornell University Press, 1967). Works
addressing this theme in agriculture include Fred A. Shannon, The Farmer's
Last Frontier: Agriculture, 1860-1897 (New York: Farrar and Rinehart, 1945);
Alan I. Marcus, Agricultural Science and the Quest for Legitimacy: Farmers,
Agricultural Colleges, and Experiment Stations, 1870-1890 (Ames: Iowa State
University Press, 1985); and David Danbom, The Resisted Revolution: Urban
America and the Industrialization of Agriculture, 1900-1930 (Ames: Iowa
State University Press, 1979), although it deals with a slightly later
period.

35 U. S. Department of Agriculture, Report to the Commissioner of
Agriculture for the year 1887, "Report of the Commissioner of Agriculture,"
by Norman J. Colman (Washington D. C. : Government Printing Office, 1888),
p. 8.

36 U. S. Department of Agriculture, Report to the Commissioner of
Agriculture for the year 1888, "Report of the Statistician," by J. R. Dodge
(Washington D. C. : Government Printing Office, 1889), p. 201.

37 Ibid., pp. 201-202. See also U. S. Department of Agriculture, Report to
the Commissioner of Agriculture for the year 1891, "Report of the
Statistician," by J. R. Dodge (Washington D. C. : Government Printing
Office, 1892), pp. 301-306.

38 U. S. Department of Agriculture, Report to the Commissioner of
Agriculture for the year 1892, "Report of the Secretary of Agriculture," by
J. M. Rusk (Washington D. C. : Government Printing Office, 1893), p. 10;
also U. S. Department of Agriculture, Report to the Commissioner of
Agriculture for the year 1893, "Report of the Secretary of Agriculture," by
J. Sterling Morton (Washington D. C. : Government Printing Office), p. 16.

39 The agricultural appropriation act of 1881 statutorily established a
divisional organization for the USDA, at which time the divisions of Seed,
Gardens and Grounds and of Botany were founded. The Division of Pomology was
established in 1886; the Division of Vegetable Pathology achieved
independence from the Division of Botany in 1891, and became the Division of
Vegetable Physiology and Pathology in 1895; in that year, the Division of
Agrostology was also founded. The Section Foreign Seed and Plant
Introduction was established in 1897. See U. S. Department of Agriculture,
Division of Publications, Historical Sketch of the U. S. Department of
Agriculture: Its Objects and Present Organization, by Charles H. Greathouse,
Bulletin no. 3 (Washington D. C. : Government Printing Office, 1898), pp.
33-40; Fred Wilbur Powell, The Bureau of Plant Industry, its History,
Activities and Organizations, Institute for Government Research, Service
Monographs of the United States Government, no. 47 (Baltimore: Johns Hopkins
University Press, 1927), pp. 1-9; and David Fairchild, The World Was My
Garden, Travels of a Plant Explorer (New York: Charles Scribner's Sons,
1939), pp. 105-107.

40 U. S. Department of Agriculture, Report to the Commissioner of
Agriculture for the year 1885, "Report of the Chief of the Seed Division,"
by William M. King (Washington D. C. : Government Printing Office, 1885), p.
47.

41 Ibid., p. 51.

42 Ibid., p. 53.

43 U. S. Department of Agriculture, Report to the Commissioner of
Agriculture for the year 1886, "Report of the Pomologist," by H. E. Van
Deman (Washington D. C. : Government Printing Office, 1886), p. 260.

44 U. S. Department of Agriculture, Report to the Commissioner of
Agriculture for the year 1887, "Report of the Pomologist," by H. E. Van
Deman (Washington D. C. : Government Printing Office, 1888), pp. 627-628.

45 U. S. Department of Agriculture, Report to the Commissioner of
Agriculture for the year 1892," "Report of the Superintendent of Gardens and
Grounds," by William Saunders (Washington D. C. : Government Printing
Office, 1893).

46 U. S. Department of Agriculture, Report to the Commissioner of
Agriculture for the year 1892," "Report of the Chief of Vegetable
Pathology," by B. T. Galloway (Washington D. C. : Government Printing
Office, 1893), p. 246.

47 B. T. Galloway, "Division of Vegetable Physiology and Pathology,"
Yearbook U.S.D.A. 1897 (Washington D. C. : Government Printing Office,
1898), p. 104.

48 Ibid., p. 106.

49 Albert F. Woods, "Work in Vegetable Physiology and Pathology," Yearbook
U.S.D.A. 1898 (Washington D. C. : Government Printing Office, 1899), pp.
264-266. See also U. S. Department of Agriculture, Report to the
Commissioner of Agriculture for the year 1899," "Report of the Secretary of
Agriculture," by James Wilson (Washington D. C. : Government Printing
Office, 1899), p. 15.

50 As illustrative of the division's work during this period and of the
intellectual problems addressed by its researchers, see Walter T. Swingle
and Herbert J. Webber, "Hybrids and Their Utilization in Plant Breeding,"
Yearbook U.S.D.A. 1897, pp. 383-421.

51 For example, see U. S. Department of Agriculture, Report to the
Commissioner of Agriculture for the year 1889," "Report of the Botanist," by
George Vasey (Washington D. C. : Government Printing Office, 1889), pp.
377-381; and U. S. Department of Agriculture, Report to the Commissioner of
Agriculture for the year 1890, "Special Report of the Assistant Secretary:
The Scientific Work of the Department in its Relations to Practical
Agriculture," by Edwin Willits (Washington D. C. : Government Printing
Office, 1890), pp. 59-73.

52 Rossiter, "The Organization of the Agricultural Sciences," pp. 213-215.

53 U. S. Department of Agriculture, Report to the Commissioner of
Agriculture for the year 1898," "Report of the Secretary of Agriculture," by
James Wilson (Washington D. C. : Government Printing Office, 1898), p. 47.

54 U. S. Department of Agriculture, Office of Experiment Stations,
Organization of the Agricultural Experiment Stations of the United States,
Norman J. Colman, Bulletin no. 1 (Washington D. C. : Government Printing
Office, 1884).

55 See Charles E. Rosenberg, No Other Gods: On Science and American Social
Thought (Baltimore: Johns Hopkins University Press, 1976), pp. 174-175.

56 This group included William James Beal, Charles E. Bessey, and Liberty
Hyde Bailey. On their efforts, see Andrew Denny Rodgers, John Merle Coulter,
Missionary in Science (Princeton: Princeton University Press, 1944), esp.
pp. 52-64, and idem, Liberty Hyde Bailey, A Story of American Plant Sciences
(Princeton: Princeton University Press, 1949), esp. pp. 22-181, 242-247. See
also Richard Overfield, "Charles E. Bessey: The Impact of the 'New Botany'
in American Agriculture, 1880-1910," Technology and Culture, 1975, 16:
162-181.

57 See U. S. Department of Agriculture, Office of Experiment Stations,
Digest of the Annual Reports of the Agricultural Experiment Stations in the
United States for 1888, Bulletin no. 2, pt. 1 (Washington D. C. : Government
Printing Office, 1884). For a discussion of constraints on scientific work
at the stations during this period, see Rosenberg, "Science, Technology, and
Economic Growth: The Case of the Agricultural Experiment Station Scientist,
1875-1914," in Rosenberg, No Other Gods, pp. 153-172.

58 The stations were South Dakota, Maryland, Massachusetts, and Mississippi.
See U. S. Department of Agriculture, Office of Experiment Stations, List of
Horticulturalists of the Agricultural Experiment Stations in the United
States, with an Outline of Work in Horticulture at the Several Stations, by
W. B. Alwood, Bulletin no. 4 (Washington D. C. : Government Printing Office,
1889).

59 Ibid. The stations were Colorado, Florida, Kansas, Michigan, New York
(Geneva), Missouri, New Jersey and Ohio.

60 U. S. Department of Agriculture, Office of Experiment Stations, List of
Botanists of the Agricultural Experiment Stations in the United States, with
an Outline of the Work in Botany at the Several Stations, Bulletin no. 6
(Washington D. C. : Government Printing Office, 1890), p. 6.

61 Ibid., pp. 7-23, for responses from the stations in alphabetical order by
state. The states with strong programs planned in crossbreeding were
Illinois, Indiana, Kansas, Michigan, New Jersey and Ohio.

62 See H. J. Webber and E. A. Bessey, "The Progress of Plant Breeding in the
United States," Yearbook U.S.D.A. 1989 (Washington D. C. : Government
Printing Office, 1899), esp. pp. 478, 480-481, 487-488.

63 Office of Experiment Stations, List of Botanists, p. 6.

64 The Illinois and Kansas stations' corn work is summarized in the U.S.
Department of Agriculture, Office of Experiment Stations, Handbook of
Experimental Station Work: A Popular Digest of the Agricultural Experiment
Stations in the United States, Bulletin no. 15 (Washington D. C. :
Government Printing Office, 1893), pp. 81-89 (entry under "Corn, crossing").

65 William Bateson, Materials for the Study of Variation (London: 1894); the
culmination of de Vries'' late-nineteenth-century work was his Die
Mutationstheorie, vol. 1 (Leipzig: 1901) and vol. 2 (Leipzig: 1903).

66 Wilfred Mark Webb, "The International Conference on Hybridisation and
Cross-breeding," Nature, 1899, 60:305-307. Others invited but not present
(in addition to Bailey) were David Fairchild of the USDA, Luther Burbank,
and J. M. MacFarlane of the University of Pennsylvania.

67 William Bateson, "Hybridisation and Cross-breeding a Method of Scientific
Investigation."

68 Hugo de Vries, "Hybridisation as a Mean of Pangenic Infection," J. Roy.
Hort. Soc., 1900, 24: 69-75.

69 C. C. Hurst, "Experiments in Hybridisation and Cross-breeding," J. Roy.
Hort. Soc., 1900, 24: 90-127. "Prepotency" suggests a sire's ability to
impress his traits on his progeny. It generally referred to an overall
"type," rather than single characters.

70 Ibid., p. 90.

71 Herbert J. Webber, "Work of the United States Department of Agriculture
in Plant Hybridisation," J. Roy. Hort. Soc. , 1900, 24: 128-145; see also L.
H. Bailey, "Progress of Hybridisation in the United States of America," J.
Roy. Hort. Soc. , 1900, 24: 209-213.

72 Willet M. Hays, "Breeding Staple Food Plants," J. Roy. Hort. Soc. , 1900,
24: 257-265.

73 See Webb, "International Conference on Hybridisation and Cross-breeding,"
p. 307.

74 Office of Experiment Stations, Experiment Station Record (1902), p. 205.

75 W. M. Hays, "Address by Chairman of Organization Committee."

76 W. J. Spillman, Mems. N.Y. Hort. Soc., 1904, 1: 155.

77 Bailey, "A Discussion of Mendel's Law," p. 450.

78 Bateson, "Practical Aspects," p. 2.

79 Bailey, "A Discussion of Mendel's Law," p. 450.

80 L. C. Dunn, A Short History of Genetics (New York: McGraw-Hill, 1965), p.
125. The following list provides a few representation comments: Paul
Mangelsdorf writes that the increased yields resulting from hybrids
"contributed not only to this country's war effort but also the
rehabilitation of Europe after the war," in "George Harrison Shull,"
Genetics, 1955, 60: 2-3. L. J. Stadler claims that "It is ... no
exaggeration to say, speaking in terms of the overall national economy, that
the dividend on our research investment in hybrid corn, during the war years
alone, was enough to pay the money cost of the development of the atomic
bomb, " quoted in G. Shull, "Hybrid Seed Corn," Sci., 1946, 103: 547-550.
Bentley Glass states that the increased in yield was "enough to pay for the
Manhattan Project" and even "most significantly, increased production
[which] permitted the United States to ship vast quantities of food abroad
after the war, thus preventing famine and pestilence," in "Shull, George
Harrison," Dictionary of American Biography, suppl. 5 (New York: Scribners,
1977), p. 629. Richard Crabb writes that hybrid corn helped "tip the scales
in our favor in a war to the finish," in Richard Crabb, The Hybrid-Corn
Makers: Prophets of Plenty (New Brunswick, N. J.: Rutgers University Press,
1948), p. 13.

81 Jean-Pierre Berlan and Richard Lewontin, "The Political Economy of Hybrid
Corn," Monthly Review, 1986, 38: 35-47; and Berlan and Lewontin, "Breeders'
Rights and Patenting Life Forms," Nat., 1986, 322, 785-788, esp. pp.
787-788.

82 They should do better, rather than equally well, because of the ubiquity
of partial dominance (discussed below).

83 G. H. Shull, "Beginnings of the Heterosis Concept," in John Gowan, ed.,
Heterosis (Ames: Iowa State College Press, 1952), pp. 14-48.

84 Shull, "A Pure-line Method of Corn Breeding," Proc. ABA, 1909, 5: 51-59.

85 Edward M. East and Donald F. Jones, Inbreeding and Outbreeding: Their
Genetic and Sociological Significance (Philadelphia: J. B. Lippincott,
1919), p. 168.

86 Shull, "A Pure-line Method of Corn Breeding," p. 52.

87 Charles Darwin, The Effects of Cross and Self-fertilization in the
Vegetable Kingdom (London: John Murray, 1876).

88 E. M. East, "The Distinction between Development and Heredity in
Inbreeding," Am. Nat., 1909, 43: 173-181.

89 Ibid., p. 177.

90 John Farley, Gametes and Spores (Baltimore: Johns Hopkins University
Press, 1982), pp. 203-208.

91 G. H. Shull, "Duplicate Genes for Capsule Form in Bursa bursa-pastoris,"
Zeitschrift für Induktive Abstammungs- und Vererbungslehre, 1914, 12:
97-149, on p. 127.

92 Ibid., p. 126; also quoted in G. H. Shull, "What is Heterosis?" Genetics,
1948, 33: 439-446, on p. 440.

93 G. H. Shull, "The Composition of a Field of Maize," Proc. ABA, 1908, 4:
296-301, on p. 301.

94 Shull, "Hybrid Seed Corn," p. 549.

95 Conway Zirkle, "Early Ideas of Inbreeding and Crossbreeding," in Gowan,
Heterosis, pp. 1-13.

96 See Frederick D. Richey, "Hybrid Vigor and Corn Breeding," Journal of the
American Society of Agronomists, 1946, 38: 833-841, and G. F. Sprague,
"Heterosis in Maize: Theory and Practice," in R. Frankel, ed., Heterosis:
Reappraisal of Theory and Practice (New York: Springer-Verlag, 1982), p. 50.

97 E. M. East, "Heterosis," Genet., 1936, 21: 375-397, on p. 375.

98 E. M. East and D. F. Jones, Inbreeding and Outbreeding.

99 The inbred plants used to produce hybrids were so depressed that they
generated little (hence expensive) seed. In the double-cross, the plants
that produce the seed are themselves hybrid.

100 "Homozygosity, when obtained with the combination of all the most
favorable characters, is the most effective condition for the purpose of
growth and reproductions," East and Jones, Inbreeding and Outbreeding, p.
187.

101 Fred Hull, "Recurrent Selection for Specific Combining Ability in Corn,"
J. Am. Soc. Agron., 1945, 37: 134-145.

102 J. L. Lush, Animal Breeding Plans, 3rd ed. (Ames, Iowa: The Collegiate
Press, 1945). Lush's influence is noted in James F. Crow, "Muller,
Dobzhansky, and Overdominance," J. Hist. Biol., 1987, 20: 351-380.

103 By 1945, 99.9 percent of corn acreage in Iowa and 98.1 percent in
Illinois and Indiana had been planted in hybrids. USDA, Agricultural
Statistics, 1947 (Washington, D. C. : Government Printing Office, 1949),
table 48, p. 43.

104 East and Jones, Inbreeding and Outbreeding, pp. 177-178.

105 Such a response occurs when there are large numbers of already existing
inbred lines, maximizing the chance of finding a favorable cross.

106 East and Jones, Inbreeding and Outbreeding, p. 182.

107 Ibid., p. 182.

108 Ibid., p. 169, 181. Jones characterizes hybrids as a "makeshift measure"
in "Selection in Self-Fertilized Lines as the Basis of Corn Improvement," J.
Am. Soc. Agron., 1920, 12: 77-100, on p. 95.

109 East and Jones, Inbreeding and Outbreeding, p. 224.

110 George S. Carter to Henry A. Wallace, 12 May 1925, quoted in Jack
Kloppenburg, First the Seed: The Political Economy of Plant Biotechnology
(Cambridge: Cambridge University Press, 1988). The Wallace papers are
deposited at the University of Iowa Library and are available on microfilm.

111 Compare Jones, "Selection in Self-fertilized Lines," p. 87, and Willet
Hays, "Distributing Valuable New Varieties and Breeds," Proc. ABA, 1905, 1:
58-65.

112 See Fitzgerald, "The Business of Breeding," esp. chap. 5 and conclusion.

113 See Kloppenburg, First the Seed, and Fitzgerald, "The Business of
Breeding."

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