24 THE soy BEAN ; HISTORY, VARIETIES, AND FIELD STUDIES. 



Trenton (S, P. I. No. 24610). — This is a brown-seeded variety 

 found by Mr. S. J. Leavell, of Trenton, Ky., in a field of the yellow- 

 seeded Mammoth. Grown sitle by side at the Arlington Experimental 

 Farm in 1909, the two varieties were indistinguishable by any other 

 character than the seed color. 



Riceland (S. P. I. No. 20797).— At the Arlington Experimental 

 Farm this variety has been grown for three seasons, and while it ma- 

 tures but few seeds it is very uniform. At Biloxi, Miss., in 1908, it 

 displayed astonishing diversity. Some plants had very narrow 

 leaves, others very broad, and all degrees of intermediates occurred ; 

 some plants were erect, others procumbent; some fruited heavily, 

 others scarcely at all. The seed was saved from individual plants 

 showing the most striking variations, and the resultant plants of each 

 in 1909 were uniform. It is possible that the seed planted at Biloxi 

 contained these forms, but the fact that the same bulk seed gave uni- 

 form plants elsewhere indicates that the diversity was a response to 

 the environment. No similar phenomenon has as yet been witnessed 

 in other varieties. 



NOMENCLATURE AND CLASSIFICATION. 



Most of the varieties of soy beans that were early introduced into 

 the United States received such names as Early Black, Medium 

 Green, Late Yellow, etc., one adjective referring to the period of ma- 

 turity, the other to the color of the seed. As long as the varieties 

 were few such a system of naming was satisfactory. 



In 1907, when the number of varieties had increased to 23, Ball" 

 recognized the impracticability of such a system of nomenclature 

 and gave single-term appellations to most of the varieties. On this 

 account, several of the older sorts are now known by two or more 

 names. 



At the present time there are known about 300 varieties, mostly 

 obtained in the last three years from Asia by the activities of the 

 Office of Seed and Plant Introduction of the Bureau of Plant Industry. 

 In the synopsis of the varieties here presented they are classified (1) 

 by the type of plant into five groups and (2) by the color of the seeds. 

 A brief description is given of each, but only the more important have 

 been given names. It will be noticed that a considerable number of 

 the varieties are not pure, containing two or more closely similar sorts 

 distinguished by the color of the flowers or the color of the pubescence, 

 or both. Thus, the Acme variety is really a mixture of four sorts, 

 namely, white flowered with gray pubescence, white flowered with 

 tawny pubescence, purple flowered with gray pubescence, and purple 

 flowered with tawny pubescence. These all mature together and the 



« Bulletin 98, Bureau of Plant Industry, 1907. 

 197 



