Apr. 15, 1914 
Coloration of Seed Coat of Cowpeas 
43 
basal-color layer and is contained in widely separated cells. It gives 
the same reaction as the yellow melanin-like pigment usually found in 
this layer. It is here, however, of a very light-straw color, this being 
due to the minute quantity rather than to any difference in character. 
This hybrid is the third generation of a cross between a Watson No. 5 
and a Taylor No. 14. The significance of the contorted cells here men¬ 
tioned should be borne in mind in view of its parentage, as it will be a 
subject for discussion under a later variety. 
No. 237-3-7 is in its general color cream white, often intensified into 
buff, or even in a few individuals distinctly brown. The color is more 
conspicuous about the hilum. Therefore, it should be classified and 
described under Division III, although in general appearance it often 
seems to be uncolored. 
II.-COWPEJAS HAVING ONL,Y ANTHOCYANIN IN THE PAUSADE EAYER 
The second group of cowpeas is that having only anthocyanin in the 
palisade cells, with a melanin-like pigment always present in the basal- 
color layer. Nine varieties were found to have enough difference in 
color scheme to be separately examined. In the first, No. 243-1-5, the 
seed coat is a strong red, varying to purplish brown. The palisade cells 
are strongly pigmented with the general color of the seed coat, so that the 
basal-color layer, which has the usual orange-yellow pigment, probably 
has little part in the general coloration, being obscured by the heavy 
pigmentation of the palisade layer overlying it. In neutral water the 
palisade pigment appears as a dull rose and slowly dissolves. Various 
reagents show it to be anthocyanin. Possibly it is mixed with a minute 
trace of buff-tinted melanin-like pigment, for there seems to remain a 
faint suggestion of a dull-buff pigmentation in the palisade cells after the 
anthocyanin has been removed. 
The basal-color layer is a strong orange yellow, the pigment being the 
melanin-like material usually found in this layer. This variety is the 
second generation of a cross of Red No. 4 on Whippoorwill No. 6. 
No. 253-2-3B-23 is a cowpea having a general blue-black tint, due to 
a speckling of deep blue on a ground color of light or dark brown, the latter 
being more or less obscured by the darker color. In sections treated with 
neutral water this pigment, an anthocyanin, shows as a strong indigo 
blue, confined principally to the lower ends of the palisade cells. No 
trace of rose-red coloration was found. Decolorized sections, if stained 
with diamond fuchsin, show an intensity of stain in proportion to the 
degree in which the cells were pigmented, and it is then more clearly seen 
that a fair proportion of these cells, certainly more than one-half, are 
without this pigment. No indication of any melanin-like pigment is 
found in the palisade layer. With hydrogen peroxid and ferric sulphate 
the palisade layer is rapidly bleached, but the basal-color layer resists the 
