50 
Journal of Agricultural Research 
Vol. II, No. i 
able in quantity. In view of the fact that one of its parents is a Whip¬ 
poorwill this unevenness of distribution of pigment in the palisade layer 
is significant. The cells of this layer are longer than usual and the taper 
of the cell cavity is somewhat sudden and blunt. There is, however, no 
contortion. There is no evidence of anthocyanin. The color in the 
basal-color layer is somewhat different in tone from that in the palisade 
layer, being a more vivid yellow, approaching orange; but both give reac¬ 
tions that indicate the pigment to be the usual melanin-like substance. 
Tests for tannin show that the basal-color layer is highly impregnated 
with this substance. The variety is a cross of Whippoorwill No. 6 on 
Clay No. 17. 
No. 216-6-4, a light-coffee cowpea obscurely streaked, shows the basal- 
color layer to be a vivid yellow, while the palisade layer is buff to brown 
and quite variable in degree of pigmentation. The pigment in both is a 
strongly granulated melanin-like substance. There is no trace of antho¬ 
cyanin. The cowpea is a second-generation hybrid produced by cross¬ 
ing Red No. 4 upon Coffee No. 16. 
No. 216-1-7 is a light to dark coffee cowpea. Closely observed, the 
seed coat shows a slight tendency to mottling. The very decided color 
of the seed coat would lead one to expect a heavy pigmentation in the 
palisade layer, but such is not the case. It is pale reddish brown, and 
not only is comparatively light, but treatment with various reagents 
fails to produce much intensification. In the basal-color layer the pig¬ 
ment is far more abundant and is confined to three or four layers, where 
it is somewhat unevenly distributed. It seems that the deep red brown 
of this cowpea is due to the pale reddish brown of the palisade layer plus 
the intense orange yellow of the basal layer. The parents are Red No. 4 
crossed upon Coffee No. 16; in other words, it is identical with those of 
the cowpea last mentioned, the variety examined being the second genera¬ 
tion of this cross. 
A most interesting cowpea, known as Old Man, bears the Government 
number 17354. It has a cream-white seed coat obscurely and faintly 
streaked with yellow brown. The deeper color is very strongly deposited 
about the hilum, so that its character can there be readily tested. Trans¬ 
verse sections of the seed coat show that in almost all instances the 
palisade cells are practically destitute of pigment. However, a minute 
quantity may be detected by very close observation, and it is observable 
that this is highly variable, even within the narrow limits just mentioned. 
In other words, it corresponds to the very obscure streaking of the seed 
coat itself. It is of a melanin-like character without any admixture of 
anthocyanin. The palisade structure is decidedly abnormal, its cells 
being much wider in proportion to their length than common, enormously 
contorted, and the unusual twisting upon the long axis is here carried to an 
extreme. The whole palisade layer is loosely put together with abundant 
intercellular spaces. The basal-color layer has an exceedingly meager 
