10 



SOY BEAN VARIETIES. 



and browns are much less common and are also very variable in 

 shade. The browns are of various shades of reddish brown and are 

 also closely related to the mottled group. The yellows vary com- 

 monly into greenish shades, and any line drawn between the yellow 

 and greenish yellow is only arbitrary. The yellows also vary into 

 paler shades, and some have even been called "white" in Japan. 

 This is most noticeable in old seeds, but is never carried farther than 

 a pale yellow. It seems likely that none of the legumes commonly 

 cultivated in Japan can have pure white seeds, like our navy beans 

 for example, or the term "white" would never be applied to a pale- 

 yellow form. All yellow soy beans turn gradually paler with age for at 

 least three or four years, although some varieties are originally paler 

 than others. Although the black group shows more variation in 



Yforrui\ 



Fig. 1. — Diagram showing the, probable relationships of the different groups of soy beans. 



the size of the seeds, the yellow is much more variable in color shades 

 and passes into green by some very fine gradations. There seem 

 to be no other characters correlated with seed colors, so that this 

 separation must be made on color alone. 



Figure 1 shows an attempt to represent graphically the relation- 

 ships and importance of the various color groups. The solid lines and 

 rectangles represent existing groups and probable relationships; the 

 dotted lines and rectangles indicate possible but still unknown groups 

 or those toward which variation seems to be progressing. The six 

 color groups recognized and described herein are as follows: 

 I. Black seeded. IV. Green seeded. 



II. Brown seeded. V, Greenish yellow seeded. 



III. Mottled seeded. VI. Yellow seeded, 



