A GENETICO-PHYSIOLOGICAL STUDY ON THE FORMATION ETC. 
51 
Name of variety 
Colour of seed 
■when mature 
Cbromogen 
P F 
in seed 
oxidation 
colour 
Chromogen in 
If. 
P F 
“ Sennari ” 
99 9 » 
— 
— 
— 
— 
Ill 
“ Kariha-tafeiya ” 
,9 99 
VI 
— 
— 
III- 
“ Shiro-nedzumi ” 
99 99 
— 
— 
— 
— 
III 
“ Fukui-shiro ” 
99 99 
— 
— 
— 
— 
IV 
“ Shonai-wase ” 
99 99 
— 
— ■ 
— 
— 
III 
“ SMro-hachikoku ” 
99 *9 
— 
— 
— 
— 
IV 
“ Abura-mame ” 
99 99 
— 
— 
— 
— 
III 
The purple and blue pigments are anthocyanins. Both anthocyanin and 
brown pigments are confined to the epidermis existing in the same cell. 
When a common black bean is boiled with an alkaline solution, the colour 
of the solution becomes blue to green at first, but soon changes to deep wine 
red owing to the extraction of the brown pigment in alkali. 
The peroxidase was tested in a number of varieties at the stages previous 
to pigmentation of the seed coat. The reaction was very distinct in the seed 
coat of all the coloured types as well as in the yellow and green ones, but 
the direct oxidase reaction failed by alpha naphtol, benzidine, myricetin and 
guaiacum. It was often noted when alpha naphtol was applied, the reaction 
was very faint in the epidermis even in the presence of hydrogen peroxide. 
There could be found no definite difference with respect to the peroxidase 
reaction exhibited by the seed coats of beans which contain the cliromogenic 
substance and those lacking it; 
In the black patched bean, however, the part where the anthocyanin 
colour will appear in a patch, yielded a deep purple or brown colour by 
immersing the whole bean which was previously treated with alcoholic solution 
of benzidine or myricetin, in a dilute solution of hydrogen peroxide. The 
remaining part where anthocyanin will not be formed at all, yielded less 
distinct colour in the case of benzidine and nearly failed in the case of 
myricetin. The cliromogenic substance was detected in the tissue of the non¬ 
black part. The alcoholic extract of the portion gave a slight red colour by 
heating with hydrochloric acid. 
The above observation seems to point out the fact that at the time of 
pigment formation, the black patched portion of the seed coat contains more 
