GOSSYPIUM 



413 



the bracts, petioles, stems, and the embryo, especially its cotyle- 

 dons. Floral nectaries occur at the base of the inner surface of 

 the calyx, and there are three sets of extra-floral nectaries located 

 on the leaf, and on the outer and inner surfaces of the involucral 

 bracts. 



The primary axis consists of two types of branches. The mam 

 stem is indeterminate with a terminal growing point, while the 

 lateral branches arising in the axils of the leaves of the main 

 stem are of two kinds, one type being vegetative and the other 

 fruiting. The vegetative branches are similar in function and 

 morphology to the primary axis, but the fruiting branches are 

 distinctive in form, function, and mode of development. In the 

 axil of each leaf there are two buds, one of which may be rudi- 

 mentary. The true axillary bud is centrally located above the 

 middle of the base of the petiole, while the lateral or extra-axillary 

 bud is to the right or left of the axillary bud. These two buds 

 differ with respect to their further development, the axillary bud 

 producing only vegetative branches or "limbs," while the branches 

 which bear flowers and fruit are developed from the extra-axillary 

 one. (Fig. 110.) 



There is some variation with respect to the axillary and extra- 

 axillary or accessory bud "development in the several varieties 

 of cotton, and in some instances, a single bud may occur in the 

 axil of the leaf. According to Templeton (34), there is a bud 

 in the axil of each cotyledon in Egyptian cotton which does not 

 develop, and each of the other leaves has a true axillary and an 

 accessory bud. In the usual development of the plant, only one of 

 the two buds in a given axil develops into a branch. Normally, at 

 the first three or four nodes above the cotyledons, the axillary 

 buds develop and the extra-axillary buds remain dormant, so that 

 a zone of vegetative branches is formed in which the branches 

 resemble the main axis in the development of nodes, leaves and 

 axillary buds. Above the fourth or fifth node, only the extra- 

 axillary buds usually develop, forming a zone of fruiting branches. 

 There may be a third or transition zone between the vegetative and 

 fruiting zones in which the buds are irregular in their behavior. 

 In this zone, both buds may become active, both may abort or 

 remain dormant, or either one of the two may develop. When the 

 vegetative branch develops, the phyllotaxy is the same as that of 

 the main axis; and the axillary buds may give rise to fruiting or to 



