Hayes and Garber - Cucurbit Breeding

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 1H m - l n S m 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 G. 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,
California.
stigmas and stamens (natural size).
(After Cook.}
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, 1919). 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-