EARLY IDEAS ON INBREEDING AND CROSSBREEDING 9 



And one sees an especially great and wonderful mystery in these spikes, Gott der Ilerr, 

 through the medium of nature which must serve everyone, disports himself and performs 

 wonders in his works and so notably in the case of this plant that we must rightly be 

 amazed and should learn to know the One True Eternal God even from his creatures alone. 

 For some of the spikes of this plant, together with their fruit, are quite white, brown and 

 blue intermixed. Thus, some rows are half white, a second series brown and the third blue; 

 and some grains, accordingly are mixed with each other and transposed. Again, sometimes 

 one, two, or three rows are white, the next rows blue, then again white and after that 

 chestnut-brown; that is, they are interchanged on one row and run straight through on 

 another. Some spikes and their grains are entirely yellow, others entirely brown, some are 

 white, brown, and blue, others violet, white, black, and brown: of these the white and 

 blue are prettily sprinkled with small dots, as if they had been artistically colored in this 

 way by a painter. Some are red, black, and brown, with sometimes one color next to the 

 other, while at other times two, three, even four colors, more or less, are found one next 

 to another in this way. 



During the next century and a half, many other descriptions of the 

 occurrence of different colored grains on a single ear were published. I have 

 found about forty of them and there are doubtless many more. The earliest 

 correct interpretation of this phenomenon had to await the eighteenth cen- 

 tury and is contained in a letter written by Cotton Mather in 1716. Here 

 the different colored grains occurring together on an ear are ascribed to a 

 wind-born intermixture of varieties. This letter is the first record we have of 

 plant hybridization, and antedates Fairchild's description of a Dianthus 

 hybrid by one year. In 1724, Paul Dudley also described hybridization in 

 maize, and he was able to eliminate one of the hypotheses which had been 

 used to explain the mixture. As a broad ditch of water lay between the mix- 

 ing varieties, he could show that the mixed colors were not due to the root- 

 lets of different strains fusing underground, a view held at the time by 

 many New Englanders, both white and red. 



Hybridization in maize was described again in 1745 by Benjamin Cooke, 

 in 1750 by the great Swedish traveler and naturalist, Pehr Kalm, and in 

 1751 by William Douglass. By the early nineteenth century, knowledge of 

 plant hybrids was widespread. Plant hybridization was becoming a routine 

 practice, and there is little doubt that different varieties of maize were 

 crossed many times by American farmers who did not record their breeding 

 experiments in writing. 



Brown and Anderson (1947, 1948) have recently shown that the modern 

 races now grown in the corn belt are derived from both the northern flint 

 and the southern dent varieties. Hybridization in corn was easy to perform 

 and the results were easy to recognize. The intermixtures of colors were so 

 spectacular that they were frequently described, by Gallesio (1806), Burger 

 (1808), Sageret (1826), Gartner (1827), and others. 



We detour briefly here into some of the technical aspects of xenia. Double 

 fertilization and the mixed nature of the endosperm were discovered by Na- 

 waschin in 1899. In 1881, Focke introduced the term xenia but he used it 

 to include what we now call melaxenia. Focke collected from the literature 



