Apr. 15, 1914 
Coloration of Seed Coat of Cowpeas 
47 
broadly flared out at the base, rapidly narrowing in the middle of the cell to 
a mere thread, and again broadening at the upper end. This irregularity 
of form should be noted in comparison with the same condition mentioned 
under other cowpeas belonging to this Watson type. In the basal-color 
layer large crystalline masses of a heavy melanin-like pigment are depos¬ 
ited in clustered cells along its upper stratum. Many of the cells are so 
scantily supplied with pigment as to appear practically colorless. The 
form of the cells is also more irregular than usual, showing a decided 
crumpling and contortion, even when expanded by means of caustic 
potash. This hybrid is the result of a cross of Sport No. 5 upon Coffee 
No. 27, third generation. 
In Sport No. 5 the seed coat varies from cream white thinly spread 
over with purplish black spots arranged on the Watson type to indi¬ 
viduals in which the purplish black pigment is so abundant as to give a 
dull purple-gray tone to the entire seed. All the cowpeas of this variety 
have a strong purplish black “eye.” In the darker individuals the pig¬ 
mented palisade cells, about one-fifth of the entire number, owe their 
color to an intense indigo-blue alkaline anthocyanin uniformly found in 
the lower third of the cells. The other four-fifths of the cells seem to 
be destitute of pigmentation. The somewhat purple tint of the seed 
coat would lead to the expectation that an acid anthocyanin would be 
associated with this blue anthocyanin, but no such color was discoverable. 
No trace of melanin-like pigment could be found in the palisade cells. 
Their shape is also significant. They are usually short, with thick walls, 
and display to a moderate degree the strange contortion in outline and 
twisting on their long axis referred to in the case of some other cow¬ 
peas. The basal-color layer is a pale or dirty lemon yellow. 
The only difference discoverable between the light and the dark 
colored individuals is the greater infrequency of pigmented cells in the 
palisade layer of the former, there being only 1 in 20 having a trace 
of the blue-black anthocyanin above noted. It is also in smaller 
quantity. A mere hint of rose-red anthocyanin seems to be discover¬ 
able in palisade cells of the lighter individuals, but this is too uncertain 
to warrant a definite statement. The cells are also unusually short, 
thick-walled, and contorted in outline. The basal-color layer is the 
same as in the other form. No accurate data as to parentage of this 
variety were obtainable. It was originally secured from Mr. J. W. 
Trinkle, of Madison, Ind., but correspondence has failed to give the 
facts regarding its origin. 
No. 22o-2-2Re, another Watson type, has a pale-buff seed coat 
irregularly streaked with dull purple. The pigment is intensified 
around the hilum, producing what is known as an “eye.” A minute 
amount of rose-red pigment is found in the upper part of the palisade 
cells. It quickly dissolves in water, leaving a dense mass of granu¬ 
lar indigo pigment in the extreme basal end of the cell cavity. A 
