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AGRICULTURAL VARIETIES OF THE COWPEA, ETC. 



Where a larger area is colored, the color tends first to cover the 

 micropylar end of the seed. A third extension of the colored area 

 appears usually in isolated blotches of varying size and position as in 

 Holstein No. 22725 (PL V). In the fourth type the whole seed is 

 colored excepting the chalazal end (PL IV, fig. 2). In these va- 

 rious distributions of the second color it is to be noted that speck- 

 ling and marbling both behave in the same manner as a single color. 



Marbling, so far as known, occurs in but four combinations — brown 

 on a buff ground, brown on pink, black on red, and buff on black. 

 Speckling occurs as blue (diluted black?) on buff and brown on 

 buff. Three varieties, Groit, No. 29295, and No. 11076B, have a 

 combination of both marbling and speckling. 



That these color distributions are really definite types would seem 

 to be proved by the fact that each type occurs in several different 

 color combinations and that no other types of color distribution 

 occur. The known results from hybridizing are all confirmatory of 

 the above conclusion. 



In unicolored seeds buff or clay occurs in more varieties than any 

 other color, followed by black and by maroon, respectively. The 

 other colors are represented by only a few varieties each. These are 

 all intergrades from white to yellowish, buff to pink, and pink to 

 maroon. Black in all cowpeas is really very dark violet, as may be 

 seen in immature seeds or in seeds that for any reason have ripened 

 prematurely. Furthermore, certain hybrids with black as one parent 

 have violet-colored seeds by dilution of the black. In several cases 

 of varieties having bluish or purplish seeds the color is not uniform 

 in shade, the depth or amount of color varying on different seeds 

 or in different parts of the same seed, or both. The presence of a 

 small amount of black blood in buff-colored varieties of hybrid origin 

 is often indicated by occasional seeds having splotches of violet, 

 especially on the ends. Some hybrids with black exhibit a dirty gray 

 or dirty violet black with a granular appearance; as, for example, 

 Watson. At times this granular coloration is similar to the speckling 

 found in Taylor, but certainly is not the same. From various hybrids 

 that have been made there are suggestions as to other interrelations 

 of the colors that occur, the complete elucidation of which will re- 

 quire much investigation. 



Some suggestions may be hazarded as to which of these colors or 

 color patterns are primitive. The evidence would seem to indicate 

 that black, black-eye, marbled, and speckled are all fundamentally 

 different, and it is doubtful if any one of these can be derived by 

 combination of pure strains of the others. The same may be true 

 of white, cream, and maroon. Buff can be obtained by crossing 

 marbled and speckled, some of the hybrids losing the markings and 



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