Agricultural History, 26(1): 2-8 (Jan 1952)
THE HISTORY OF THE COMMON MAIZE VARIETIES OF THE UNITED STATES CORN BELT
EDGAR ANDERSON
Missouri Botanical Garden and Washington University, Saint Louis, Missouri
AND
WILLIAM L. BROWN
Pioneer Hi-Bred Corn Company

The golden yellow maize in the corn belt of the United States, the long cylindrical ear which has become the very foundation of the Nation's agricultural economy, is frequently said to be the gift of the American Indian. As we shall show below, this characteristic type of maize was not known to the Indians and came into being along with the corn belt itself during the nineteenth century. One could much more accurately say that maize as we know it in the United States is the gift of the pioneers.

The common yellow dents which dominated the chief maize production centers for fully a half century before hybrid corn appeared on the scene were variable to an extent which can scarcely be appreciated by those who have not studied such fields. They differed from plant to plant in the same field, from field to field of the same variety, and from variety to variety. Yet in spite of this variation they had a conspicuous core of generally prevalent characters. Compared with maize in other parts of the world they were a well-marked and very definite entity. They tended to have one well-developed ear, with a nubbin or small ear at the node below it. The ears had large and nearly cylindrical red cobs. The golden yellow kernels, pronouncedly dented at the tip, were set in from 14 to 22 straight rows. The whole ear had a slight tendency to taper toward the apex and for the rowing of the kernels and the diameter of the cob to be somewhat differentiated in its lowermost quarter. The plant itself had a single stem, leaves with tight sheaths, and strong arching blades, and a heavy many-branched tassel. A flush of epidermal color was apparent on the culm and leaves at the base of the plant, but seldom or never were there to be found the brilliant foliage colors so characteristic of maize in Latin America.

1 John Lorain, "Observations on Indian Corn and Potatoes," Philadelphia Society for Promoting Agriculture, Memoirs, 3: 308-310 (Philadelphia, 1814).

There cannot be the slightest doubt that these corn-belt varieties were the creation of the nineteenth century. They came in large part from crosses between white southern dents, mostly of Mexican origin, and the long, slender northern flints which had dominated the eastern United States for at least some hundreds of years preceding the discovery of America. These flints are strikingly similar to the common yellow flints of the Guatemalan highlands, strikingly unlike most Mexican maize, and are one of several cultural traits which apparently spread from the Mayan area to the eastern United States without leaving any clear record of the route by which they came. The northern flints were very different from the southern dents, and the hybrid vigor which resulted from mixing these diverse types was soon noted by alert agriculturists. While some of the blending of flints and dents may have been haphazard or accidental, much of it was directed and purposeful. The benefits to be gained were listed and the exact effects of continued mixing and of backcrossing were discussed as early as 1813.1 This intelligent controlled hybridizing proceeded until the new yellow dents were so ubiquitous that their very origin was largely forgotten. This neglect of historical tradition was unfortunate. Most maize breeders have not understood that the hybrid vigor they now capitalize is largely the dispersed heterosis of the flint-dent mongrels. Maize geneticists are for the most part unaware that the germ plasm they use for fundamental studies is grossly atypical of germ plasms in general.

2 William L. Brown and Edgar Anderson, "The Northern Flint Corns," Missouri Botanical Garden, Annals, 34:1-29 (1947).
3 Volney H. Jones, "Maize from the Davis Site: Its Nature and Interpretation," Society of American Archaeology, Memoirs, 5: 241-249 (1949).
4 Edgar Anderson and William L. Brown, "The Origin of Corn Belt Maize and Its Significance in Heterosis," Heterosis (Ames, Ia., 1952), ed. John W. Gowen, chapter 8.
5 F. W. Waugh, Iroquois Foods and Food Preparation (Canada Department of Mines, Geological Survey, Memoir 86, Ottawa, 1916); and Arthur C. Parker, Iroquois Uses of Maize and Oilier Food Plants (New York State Museum, Bulletin 144, Albany, 1910).

These distinctive wide-kerneled, long-eared varieties of northern flints (with which should be associated the related flour corns of the eastern Indians since they differ from them by but a single gene) were for centuries the prevailing type in eastern North America. We have already reported on a survey of all the readily available archaeological material.2 For most of the States east of the Mississippi the northern flints represent the only type that is known archaeologically and the only one represented in collections made among the eastern Indians. With the additional records which have come to hand since our earlier report,3 they are known archaeologically from over twenty-five sites from Massachusetts to Texas and from South Dakota and Michigan to Alabama and Georgia. A collection of sacred flour corns of the New York State Indians presented to us by Frank P. Bussell are all of this type as are varieties we ourselves collected among the Sac and Fox Indians of the Tama (Iowa) Reservation and from the Cherokee remnant in North Carolina.4 The varieties illustrated by F. W. Waugh for the Iroquois of Canada and by Arthur C. Parker for the Iroquois of New York State are nearly all of this type.5 A special collection made for us by Father Brinker on the Menominee Reservation in Wisconsin is all of this type.

6 George F. Carter and Edgar Anderson, "A Preliminary Survey of Maize in the Southwestern United States," Missouri Botanical Garden, Annals, 32: 297-322 (1945).

The only exceptions to the prevalence of northern flints in the eastern United States are in Illinois, Missouri, Ohio, and Arkansas where remains of varieties resembling those of the Great Plains and the American Southwest have been discovered. In the Southwest, corn has had a long and complicated history with a succession of types which is now fairly well understood.6 On the Great Plains, maize has had an equally complicated career with northern flints, Mexican-like dent corns, and mixtures resembling Puebloan varieties all being found in close proximity to one another but usually at different sites. Not until this large area has been much more carefully studied and the sequences and relationships of its various cultures at least approximately determined will it be possible to say anything very definite about the history of maize in the Great Plains. As to the northern flints we know that they were important there, particularly in the north, and that intermediates between them and Great Plains types are found in the central Mississippi Valley.

7 Jonathan Carver, Three Years Travels Through the Interior Parts of North-America (Philadelphia, 1796), 346-347.

All the early travelers to the eastern United States, if they mention maize at all, described northern flint varieties. Jonathan Carver, for instance, who traveled from the Atlantic coast to the western end of Lake Superior, described the maize of the Indians as having "seeds as large as pease, and like them quite naked and smooth, but of a roundish surface, rather compressed. One spike generally consists of about six hundred grains, which are placed closely together in rows to the number of eight or ten, and sometimes twelve."7

8 John Lorain, Nature and Reason Harmonized in the Practice of Husbandry (Philadelphia, 1829), 203.

John Lorain of Pennsylvania listed five types of maize which were being grown in the middle and southern Atlantic States in the early 1800s.8 Four of these were northern flints, "the big white and yellow," and "the little white and yellow." These he described as follows:

The cobs of the two first mentioned are thick and long, the grains are much wider than deep, and where the rows of grains meet and unite with each other, their sides fall off almost to nothing .... As the little white and the little yellow are formed much in the same way, and the cobs [are] considerably smaller, they are still less productive than the big white and yellow, but ripen earlier. The grain of those four flinty corns are very firm, and without indenture in their outside ends.

If the northern flints probably came from Guatemala, the southern dents even more certainly stemmed from Mexico. An ear of the variety Hickory King can scarcely be distinguished from the narrow-ear varieties of western Mexico. Shoepeg is very similar to the widespread Mexican variety Pepitillo, and gourdseed closely resembles many of the large-eared, soft-kerneled, many-rowed dents which seem to trace back to crosses between Mexican Pyramidal types and Zapaluta Chica from Oaxaca. Whatever their origin, there is as yet no archaeological evidence for any of these types within the boundaries of the United States. Dent corns are found prehistorically on the Great Plains and in the southwest, but they are different types of corn and only remotely related to these southern dents.

9 Robert Beverly, The History and Present State of Virginia (London, 1705), pt. 2, p. 30.

Apparently the oldest reference to the southern dent corns is in Robert Beverly's history of Virginia, written in 1705. He described "a larger grain and looks shriveled with a dent on the back of the grain as if it had never come to perfection; and this they call She corn."9

10 Dumont de Montigny, Memoires historiques sur la Louisiane ... (Paris, 1753), 32-34.

Our second earliest account is from the Memoirs of Dumont, published in Paris in 1753. He described the two main kinds of maize in Louisiana.10

On distingue deux sortes de mahi, dont l'un est propre a faire de la farine & l'autre non: ce dernier a le grain tout rond; l'auture l'a un peu plus plat, & se distingue par une espece de coup d'ongle ou de rainure que regne sur toute a longueur des grains.

The claw point or groove serves to distinguish the southern dents which are still to be found in that region. It would not, however, distinguish between any of the various rough dents as, for instance, the gourdseed and the shoepeg.

11 Carl Raymond Woodward, Ploughs and Politicks: Charles Read of New Jersey and His Notes on Agriculture, 1715-1774 (New Brunswick, N. J., 1941), 286.

One or two fleeting references in the recently published notebooks of Charles Read are of interest because in them we find the term dent corn used for the first time. His reference to the long kernel is also suggestive. In January 1756, he entered in his notebook the weights per bushel of various kinds of corn in New Jersey and Pennsylvania. Two of the entries could not possibly refer to flint corn: "Egg harb[o]r dented yellow 57 lb .... The Long grained Lower Co Corn clean 53."11

12 Lorain, "Observations on Indian Corn and Potatoes," Philadelphia Society for Promoting Agriculture, Memoirs, 3: 303-325.
13 Lorain, Nature and Reason Harmonized in the Practice of Husbandry, 201-229.

It is not until we come to the works of John Lorain that we have a really definite description of a southern dent. In 1813 he contributed a paper on the effect of crossing dent and flint corns which was published in the Memoirs of the Philadelphia Society for Promoting Agriculture.12 In 1825 his widow published his much more extensive treatise on agriculture, entitled Nature and Reason Harmonized in the Practice of Husbandry. It includes his earlier observations and has an even more extended discussion of maize and maize breeding.13

Lorain distinguished five kinds of maize used for field planting, one of which is the Virginia Gourdseed. His description of the ears of this corn reads:

The ears of the Virginia gourdseed are not very long, neither is the cob so thick as that of the big white and yellow. But the formation of the grain makes the ear very thick. They frequently produce from thirty to thirty-two, and sometimes thirty-six rows of very long narrow grains of a soft open texture. These grains are almost flat, at their outside ends, are also compactly united from the cob to the surface of the ear, without any of that fluted appearance between the rows of grain, which causes the flinty corns to be much less productive in proportion to the size of the ears.

14 Ibid., 203.

The gourdseed corn ripens later than any other, but it is by far the most productive. It is invariably white, unless it has been mixed with the yellow flinty corns. Then it is called the yellow gourdseed, and too many farmers consider it and most other mixtures original corns. I have often heard of original yellow gourdseed corn, but after taking much trouble to investigate the fact, could never find any thing more than a mixture. If there be an original yellow gourdseed corn, it has eluded my very attentive inquiry from the Atlantic to our most remote western settlements.14

15 Peter A. Browne, "An Essay on Indian Corn," Farmers' Cabinet, 2: 75-77, 90-92, 123-125, 139-141, 150-152, 187-190 (Philadelphia, 1837-38). The quotation is from page 150.

In 1837 and 1838 appeared the text of a lecture on maize given by Peter A. Browne before the Cabinet of Natural Science of Chester County, Pennsylvania, at which he exhibited specimens from his collection of maize varieties.15 He referred to a yellow corn as "the genuine gourd seed," though probably as suggested by Lorain and others these yellow gourdseeds all came from mixtures of white gourdseed and yellow flint. He described it as

The genuine gourd seed Indian corn, so called from the supposed similitude in shape, between its grains and the seeds of the gourd; the spike contains, when thus unmixed with any other variety, twenty-four rows, which is the highest number of rows on any cob of Indian corn I have ever seen. I have heard of twenty-six rows.

16 D. J. Browne, "A Memoir on Maize or Indian Corn," in Joel Barlow, The Hasty-Pudding: A Poem (New York, 1856), 15-48. The quotation is from page 47.

Gourdseed is described in D. J. Browne's memoir16, of 1856, though in language so similar to Lorain's that one wonders if Browne had any firsthand knowledge of the variety. His account reads:

Virginian White Gourd-Seed Corn.—The ears of this corn, which are not very long, neither is the cob so large as those of the big white or yellow flint, contain from twenty-four to thirty-six rows of very long, narrow grains of so soft and open a texture, that they will not bear transportation, by sea .... These grains at their exterior ends are almost flat, and grow so closely together from the cob to the surface, that they produce a greater yield than any other variety .... The colour of this variety is always white, unless it has been crossed with other kinds.

17 J H. Salisbury, "Maize, or Indian Corn," New York State Agricultural Society, Transactions, 8(1848); 678-873.

In 1848 J. H. Salisbury monographed the kinds of maize known to him and included the White Virginia Gourdseed among the varities with white kernels and a red cob.17 He described the variety as follows:

Length of ears from 6 to 10 inches, diameter from 2 to 2 inches. Cob light red, of medium firmness and thickly set with kernels considerably indented. Ear tapers gradually from base to summit. Depth of kernels, 6 lines, breadth in widest part, 4 lines, in narrowest part 3 lines. Chit nearly as long as the kernel.

18 U. S. Patent Office, Report, 1857, Agriculture, 163-164.

In the report of the United States Patent Office for 1857 there is a chemical analysis of "Gourdseed, or Horse-tooth Corn" from Virginia in which the variety is described as being 18-rowed with large pitted grains, nearly white, on a short stumpy ear.18

When E. L. Sturtevant monographed the corn varieties of the United States he included a number of southern dents. A gourdseed was No. 41 in his collection and a shoepeg No. 42.

41. White Maryland Gourd Seed, Landreth. Synonyms, Thompson Dent, Mo. Agr. Coil., and also "common" from Tennessee. Ear seven to eight inches long, and two and three-eights inches in diameter. Ear tapering, rounded at butt and at tip, which is unfilled. Sixteen-rowed. Kernel, white above, horny [honey] white below, long, dimple-dented, often pinched flat. Plant about nine feet tall, and bearing its ears about forty-eight inches from the ground.

19 E. L. Sturtevant, in New York State Agricultural Experiment Station, Annual Report, 1884, 179-180.

42. Shoe Peg. From N. C. Ear about seven inches long, and two inches in diameter. Ear slightly tapering, rounded evenly at butt and tip, the latter unfilled and projecting; sixteen to 20-rowed. Kernel very deep and narrow, flat, deeply dimpled-dented white above, honey white below.19

The mixing of the southern dents and northern flints began so early that it has been largely forgotten. The often-told story of the origin of Reid's Yellow Dent from a more or less accidental interplanting of an early and a late varitey is merely one of thousands of such mixtures and took place relatively late in the history of corn-belt dents. As early as 1813 John Lorain advocated the hybridization of flints and gourdseed and described the results of such mixtures. In his posthumous volume on agriculture, he expanded these ideas even further. After alluding to the mixtures of gourdseed and flint which were already prevalent in his day he described how they are produced when varieties are planted near each other.

This [the pollen] is wafted far by high winds, and is the cause of distant and unthought of mixtures. However, in general it is lightly and plentifully diffused through the field, and lodges in sufficient quantities on the silky fibers which project from the ears. A single fibre proceeds from each grain .... The change produced by this mysterious cause is generally gradual. We first see scattering whitish looking grains on the ears of the yellow corn growing among the white, and the reverse on the ears of the latter, when grown near to the yellow corns.

The foregoing facts have induced me to make experiments. The result seems to determine, that if nature be judiciously directed by art, such mixtures as are best suited for the purpose of farmers, in every climate in this country where corn is grown, may be introduced. Also, that an annual selection of the seed, with care and time, will render them subject to very little injurions change; provided the desirable properties of any of the various corns be properly blended together. They do not mix minutely, like wine and water. On the contrary, like mixed breeds of animals, a large portion of the valuable properties of any one of them, or of the whole fine original corns commonly used for field planting, may be communicated to one plant; while the inferior properties of one, or the whole, may be nearly grown out.

20 Lorain, Nature and Reason Harmonized..., 205.

In doing this, it would seem that the colour of this mixture may be either the purest white, or a yellow, nearly, or perhaps quite, as deep and bright as the colour of the flinty yellow corns: also, that the economy of the plant formed by these mixtures may be rendered sufficiently early to ripen in any climate that is not very unfriendly...20

Lorain described in detail the results of using more or less gourdseed in the mixture.

The quantity of the gourdseed corn mixed with the flinty yellow corns, may be determined, so as to answer the farmer's purpose. When the proportion of the former greatly predominates, the grains are pale, very long and narrow, and the outside ends of them are so flat that but little of the indenture is seen. As the portion of gourdseed decreases in the mixture, the grains shorten, become wider, and their outside ends grow thicker. The indentures, also, become larger and rounder, until the harder corns get the ascendancy. After this, the outside ends of the grains become thicker and more circular. They also grow wider, and the fluted appearance between the rows increases. The indentures also decrease in size until they disappear, and the yellow, flinty variety is formed. But, as I believe, not so fully but that the latent remains of mixture will forever subject it to more or less change.

Henry A. Wallace has called our attention to an article in the Disseminator of New Harmony, Indiana, for May 30, 1835, based upon an article in the American Farmer. It not only describes the crossing of different varieties but gives directions for detasseling and the production of first generation hybrid seed.

21 Disseminator (New Harmony, Ind.), May 30, 1835.

It is a cross between the early yellow Canada and the large white Tuskarora corn and partakes of the peculiar character of both .... That others may be enabled to make these improvements the process pursued will be repeated: --...  It is only necessary to plant a patch of the Canada in the usual way, and every alternate hill of every third row with Tuskarora corn. When the male flowers (the tassels) of the Tuskarora make their appearance, carefully pull them out; this must be done as soon as they appear or the experiment will fail. In this process, a moment's reflection will show, the surrounding Canada corn will supply the pollen from its tassels and consequently the product will be a perfect cross between the two kinds.21

Browne, in the lecture on maize already alluded to, referred to the effects of mixing gourdseeds with other varieties. He described the mixture of King Philip 8-row flint with gourdseed as being desirable and indicated that varieties Nos. 2 to 6 in his collection "are the products of these essays."

22 U. S. Patent Office, Report, 1850, Agriculture, 232, 245, 301, 371, 396, 400, 454, 460.

A change in administrative procedure provides us with an unusually complete picture of maize and maize breeding in 1850. In those years the United States Patent Office sent out questionnaires concerning the state of agriculture throughout the Nation. The replies, together with outstanding articles from the agricultural press, were worked up into a general summary. For the year 1850, the replies were printed, apparently with no more editing than punctuation and spelling and are not even assembled by States.22 Since one of the questions asked "what kind of corn is most esteemed in your vicinity" the replies from several score of the country's best farmers give a detailed and factual picture. Flints were widely grown not only in the North but also in the South, (New England, New York, Ohio, Illinois, Virginia, Kentucky, South Carolina, Mississippi, Alabama) and gourdseeds or mixtures with them are mentioned for nine States (New York, Ohio, Illinois, Pennsylvania, Indiana, Kentucky, South Carolina, Mississippi, Alabama). For all the country except New York and New England there is detailed evidence of the purposeful blending of diverse varieties, particularly of gourdseed and flint. Interest in corn breeding seems to have been particularly active in Ohio, and there are two mentions of mixtures. A farmer of Erie County wrote: "We cultivate several varieties of what is here called gourd-seed. They are all nearly a hybrid between the rough gourd-seed of the South and the flints of the North." Two writers from Springfield echoed the same opinion: "Varieties obtained by mixing the large Southern corn with that of the North;" and "We have many varieties of this grain, mostly crosses between the gourd-seed and small flint." In 1850 there was only one reply from Illinois. It described the most esteemed variety as "A species obtained by mixing the large yellow corn of Kentucky with the yellow flint, called here smooth yellow; it is prolific, full, smooth grain, covers the end of the cob, hard, sweet--cob brittle." From Iowa we get a glimpse of the way such mixtures came about: "The variety most esteemed here is white with a red cob, though a yellow corn, lately introduced here from South Carolina, is the most productive; but it is sometimes injured by frosts." Evidence for hybridization comes from the Southern States as well. A writer at Dunlapvile, South Carolina, referred to "the gourd-seed, or between that and flint." A reply from the Chester district in the same State goes into much more detail: "Our seed is so generally mixed, that it is hard to give it any known name; the old gourd-seed kind is gone very much out of use." He listed their best variety as "a mixture between the old gourd-seed and the low country flint-corn." From Alabama came the opinion that a "mixed kind of corn, of the flint and gourd-seed, is the best," and another Alabama writer told of breeding a new variety by mixing a small early yellow flint with a bigger and starchier "red blaze variety."

23 See Everett E. Edwards, "Reid, James L ...,"  Dictionary of American Biography, 15:477-478 (New York, 1935), and the references cited there.

The history of Reid's Yellow Dent goes back to the 1840s.23 In 1846, Robert Reid took a late, rather light reddish colored variety, the Gordon Hopkins, from Brown County, Ohio, to Illinois. Because of a poor stand the next year, a small early yellow variety, probably a flint, was used in replanting the missing hills. The family continued to grow the mixture; in 1893 Robert's son, James, won a prize with it at the World's Fair, and the variety became so widely grown that it dominated the corn belt.

The shuffling and reshuffling of these two basically different germ plasms continued, though in the north the term gourdseed was practically forgotten. The agricultural papers and the seed catalogs for the last half of the nineteenth century are full of references to the new varieties which were produced by hybridization and selection. George Kurtzweil has supplied us with the definite information that S. S. Barr of Davenport, Iowa, the creator of the dent variety, Golden West, was using bags to cover the tassels and produce controlled pollinations as early as the 1870s.

24 Edgar Anderson, "The Sources of Effective Germ-Plasm in Hybrid Maize," Missouri Botanical Garden, Annals, 31: 355-361 (1944).

We have given detailed evidence elsewhere concerning the origin of Lancaster Surecropper, a dent variety of rather minor importance until various experts in the United States Department of Agriculture demonstrated that it was a particularly good source of inbred lines for modern corn breeding.24 It was started in the 1860s from crosses between the common corn of the community, a large, late, rather rough dent, with a small, slender-eared corn which the Hershey family got from the Patent Office. They continued to cross other varieties into the mixture from time to time and selected seed ears which yielded well without any regard for ear or kernel type.

The controlled breeding of new varieties by farmers themselves was more frequent than anyone would believe who has not looked into the record. During the last five years we have attempted to interview as many of those farmers whose corn placed well in the early Iowa yield tests as could be located conveniently. We have been struck by the high proportion of them who began their work by the deliberate crossing of two or more varieties. Some of these men had highly elaborate methods of selection. Clyde Black, whose corn did phenomenally well in the early Iowa yield tests, had practiced a modified ear-to-row selection method with an ear-to-row plot located in the center of his regular corn field. He began with a smooth dimpled dent which had won the bushel championship in 1908. Two years later he obtained the much rougher (i.e., more deeply dented) variety, Iodent, and after three years of growing the two kinds separately, each with its own breeding plot, he shelled both kinds and planted them together, putting the best ten ears into a breeding plot. Rex Richards, who showed in corn shows from 1915 to about 1939, bought his corn from Proudfit and from J. A. Mason. He mixed the seeds and from then on practiced ear selection in the field. Our interview with Fred McCulloth is of particular interest because he was one of the few who produced a corn which placed well in shows, yet which was demonstrated to have good yield when the Iowa tests were initiated. McCulloch got his start from his father who in the early 80s had planted a 35-acre field with alternate rows of a yellow Learning and the variety, Pride of the North, both of them purchased locally. Field selections out of the mixture were made first by the father and then by the son. In 1903 the latter interplanted with a strain of Reid's dent from Illinois and a year later with an Iowa strain of Reid. He then practiced ear-to-row selection, planting his rows in a separate plot and detasseling part of the plants. He bought good ears very widely from corn shows and put their seeds into his selection plot. Every year he made in the neighborhood of twenty ear-to-row tests and roughly half of the ears tested were from shows.

The northern flints were once the prevailing type of maize throughout the eastern United States, with an archaeological record taking them back at least to 1000 A.D. There is as yet no evidence for their having been preceded in that area by any other type of maize or of Mexican-like dents having been used there in pre-Columbian times. The Northern flints belong to a type of maize rare or unknown over most of Mexico but common in the highlands of Guatemala. The southern dents, on the contrary, are obviously largely derived from Mexican sources and by 1700 were being grown as far north as Louisiana and Virginia. As to how and when they spread northward from Mexico we have no evidence, other than the negative facts that they are not known archaeologically from the eastern United States and are not represented in the collections of Indian varieties from that region. As early as 1800 the benefits of crossbreeding these two different types of maize were appreciated by at least a few experts, and by 1850 the process was actively under way from Pennsylvania to Iowa and south to the Gulf States. By the 70s and 80s a new type of corn had emerged from this blending, though crossing and recrossing of various strains continued up to the advent of hybrid corn. During the latter half of the process, the origin of corn-belt dents from fifty to a hundred generations of selective breeding of crosses of northern flints and southern dents was almost completely forgotten.

25 Anderson and Brown, in Heterosis, chapter 8.

The open-pollinated varieties of maize which dominated the corn belt of the United States for over half a century were the creation of pioneer farmers and corn breeders. It was from them that our modern hybrid corn is in large part derived. We have discussed elsewhere the bearing of these facts upon maize breeding and maize genetics.25 The actual historical facts, as we have shown, are cross-checked by indirect evidence from cytology and from genetics. They outline an important field of investigation which it is the province of a trained agricultural historian to explore in full.