A OKXETrCO-rHYsroLOrilCAT, MTrnV ox the FORMATrriN ETC. 49 



5. Greeu. 

 (j. Yellow. 

 IT. P!U-ti-cül(jur type. 



1. Bliu-k mottled, the ground colour brnwu with or without a gi'een 



tiuge. 



2. Black p:itch arouud the liiluiu. The gi'ouud cok>ur is either 



yellow or greeu. 



3. Dark browu patch around the hilutu, the gi'ound colour is either 



green or yellow. 



4. Blue tiuged around the liilum. The gi'ouud colour either greeu 



or yellow. The margin of the Muo tiuge is not so distinct as 



in 2 and 3. 

 The chromogen can be detected in the imiuatm-e gi'eeu seed of all the 

 coloured tj-pos, except the gi-een and yellow. Tli3 chromogenic substance P 

 is abundant but the chromogenic substance F is very scarce or absent. In 

 the green and yeUow, both are nearly absent. Heuce the different types cau 

 be distinguished into two gi-oups vdih. resi^ect to the clu'omogen. One includes 

 those ■which give a marked chromogen reaction -when the seed is still gi-eeu 

 and the other includes those which give only a shght or no reaction. In 

 this regard, the gi-een and yellow c-oiTespoud with the wliite tv^pe of the 

 common garden Ijeau and Adzuld-bean (see Tables 8, 9). 



Since the reaction of the chromogenic substance F is feeble in the seed 

 just before the formation of the pigment, the latter must be formed fi-om the 

 duromogenic substance P which is present. In the leaf, however, the 

 chromogenic substance F occurs in a considerable amount and can readily be 

 isolated as yellow ciy-stals. The following table will give a general idea of 

 the distribution of the chromogeus in the seed coat and the leaf of different 

 varieties of soy-l>eans. 



