COTTON AND SORGHUM 175 



size of a small hen's egg and is closely filled with seeds. It is 

 composed of from three to five cells. When ripe the boll turns 

 brown and splits open and the lint and seed are exposed. 

 The seeds, each about % in. long and half as wide, are covered 

 with lint and fine fuzz. This lint, the cotton of commerce, is 

 from % to IK m - long in the ordinary varieties. (Wilson and 

 Warburton, 1919). G. barbadense is distinguished in part from 

 G. hirsutum by its greater height, longer branches, longer and 

 finer fiber, and seeds free from fuzz. Egyptian is generally 

 considered a variety of (7. barbadense. It is the variety grown 

 largely in Egypt, also under irrigation in Arizona and southern 



FIG. 41. View of flower of cotton, from above, showing position of petals, 

 stigmas arid stamens (natural size). (After Cook.) 



California. India cotton (G. herbaceum) has stems more slender 

 than upland, and leaves with rounded lobes and smaller, less 

 pointed bolls. The lint is white, yellow, or brown. Its cultivation 

 is confined to southern Asia (Wilson and Warburton, 19 19) . Balls 

 (1908, 1911, 1912) and Leake (1911) have investigated color 

 inheritance of seed fuzz, lint, anthers, flowers, and sap. In 

 most cases the second generation gave a mono- or di-hybrid ratio. 

 On the other hand, ratios were also obtained which were not easily 

 explained on a simple factor basis. The inheritance of the red 

 spot on the petals of some varieties involves two factors with a 

 3:1:1:3 coupling. Red spot on the leaf showed simple mono- 



