Apr. is, 1914 
Coloration of Seed Coat of Cowpeas 
53 
but where the basal color is pale buff instead of red brown it is very 
deficient. The deeper tint of the basal color in some seeds is therefore 
due, at least in part, to a greater quantity of pigment in the basal-color 
layer rather than to any difference in the pigmentation of the palisade 
layer. This is the reverse of what is usually found in cowpeas of variable 
tint, their difference usually being brought about by variation in the 
degree of the pigmenting of the palisade cells superimposed upon a 
uniformly pigmented basal layer. The black areas are due to a dense 
blue alkaline anthocyanin confined to the lower third of the cavity of 
the pigmented cells and so heavily deposited that only long action by 
different reagents brings about the usual changes. The brassy yellow 
pigment also contained in the palisade cells gives the usual reactions. 
It is strongly granular and in unusually large quantity. It is well to note 
the presence in the same cells of these two forms of pigment in con¬ 
nection with the fact of the very slow response of the anthocyanin to 
the usual reagents, as this behavior will be commented upon in other 
cases. The form of the palisade cells is slightly irregular, but not 
exceedingly so, and this is confined almost entirely to the lighter portions 
of the seed coat. The parentage is White No. 7 crossed upon Black 
No. 22, second generation. 
Cowpea No. 14 has a pale-buff to red-brown basal color, strongly 
speckled with black spots on what is known as the Taylor pattern. In 
individuals of the lighter basal color we find that the palisade cells in 
the ground-color areas are so nearly destitute of pigment that it is diffi¬ 
cult to discover its presence. The basal-color layer is also a dirty 
yellowish brown instead of the stronger brown that would be expected. 
The areas spotted with black owe this color to an intense blue antho¬ 
cyanin in the lower half of the cavity of the palisade cells, the proportion 
of these to uncolored cells being about as 1 to 5. The anthocyanin 
extends up in these cells much higher than in most cases, sometimes 
reaching the upper end of the cavity. In individuals having the darker 
ground color, the presence of melanin-like material in the palisade cells 
is very evident and the basal-color layer is seen to be much more strongly 
tinted with a strong copper-colored melanin-like pigment. In this cowpea 
we again find that only by long treatment will the usual reagents bring 
about the expected reactions on the anthocyanin. Caustic soda, hydro¬ 
chloric acid, chloral hydrate, etc., are very sluggish in the changes 
produced, so that there seems to be an impediment in the way of their 
reacting upon this sensitive material. The palisade cells in both dark 
and light varieties are long, narrow, evenly tapered, and symmetrical. 
No data have been secured as to the parentage of this variety. 
No. 237-3-2 also ranges from pale buff or clay to strong red brown 
and is speckled with black. The black color is due to a blue alkaline 
anthocyanin deposited as usual in the lower end of the palisade cells, 
and in this case also the reagents are extremely slow in producing results 
