Apr. is, 1914 
Coloration of Seed Coat of Cowpeas 
4 1 
CLASSIFICATION OF COLOR FACTORS IN COWPEAS 
For convenience of reference, the foregoing factors of coloration in 
cowpeas may be classified as follows: 
I. Basal-color layer. 
a. Devoid of pigment (white). 
b. With melanin-like pigment (buff to brown), 
II, Palisade layer. 
A. Solid colors. 
a. Melanin-like pigments. 
a / . Buff, clay, etc. 
b'. Coffee, brown, etc. 
b . Anthocyanin pigments. 
a'. Red (acid state). 
V. Blue (alkaline state). . 
cf . Purple (combination of a? and b '). 
d'. Black (intensification of b' or cf). 
B. Variegated colors. 
a. Marbling. 
of. Affects melanin-like pigments only. Whippoorwill type. 
b. Speckling. 
of. Deep-blue anthocyanin in groups of cells; groups widely scattered. 
Taylor type. 
y. Same, but groups more plentiful. New Era type. 
c. Marbling and speckling. 
C. Eyed. 
a. Watson type of eye. Margin of eye indefinite. 
b. Holstein type of eye. Seed of eye indefinite. 
c. Narrow eye. Narrow patch of color about the hilum-indefinite at lower 
end (micropylar). 
d . Small eye, due to presence of both a and b. 
e . Very small eye, due to the presence of both a and c. 
D. Dilute colors. 
Characterized by individual unpigmented cells scattered among pigmented 
cells over entire seed coat. 
CLASSIFICATION BASED ON DISTRIBUTION AND KINDS OF PIGMENTS 
For convenience in grouping, the writer has divided the different varie¬ 
ties into four classes: (1) Those with or without a pigment in the basal- 
color layer, but none in the palisade layer; (2) those in which there is a pig¬ 
ment in the basal-color layer and anthocyanin only in the palisade layer; 
(3) those in which there is pigment in the basal-color layer and a melanin¬ 
like pigment only in the palisade layer; and (4) those in which there is a 
pigment in the basal-color layer and both anthocyanin and a melanin¬ 
like pigment in the palisade layer. 
I.—COWPEAS HAVING NO PIGMENT IN THE PALISADE LAYER 
Under the first division I have found, as previously stated, one cow- 
pea, No. 0632, which is an extreme type of albinism. Here both the 
palisade and basal-color layers are destitute of. all pigmentation. The 
