DIMORPHIC BEANCHES OF THE COTTON PLANT. 15 



other a sterile limb with leaves only. It was noticed also that the 

 branches that bear the flowers arise in the same position as the flowers 

 themselves — not in the axils of the leaves, but at the side of the 

 axillary bud. 



The axillary branches of cotton function normally as equivalents 

 of the main stem in the sense that they do not bear any flowers or 

 fruits except in the indirect way of producing other branches of the 

 fertile sort from extra-axillary buds. Fertile branches borne by the 

 main stem of a cotton plant may be called primary fruiting branches; 

 those that come from limbs may be called secondary fruiting 

 branches. Normal fruiting branches of both kinds bear a flower bud 

 at each node. Secondary limbs may be produced from primary 

 limbs, or even from axillary buds of the fruiting branches, especially 

 if a plant has been injured or pruned or suddenlv forced into renewed 

 growth late in the season. Only in rare and abnormal cases is a flower 

 borne directly on a branch that arises from an axillary bud. 



It is the normal habit of some varieties to develop vegetative limbs 

 from axillary buds along with the fruiting branches that come from 

 the extra-axillary buds, as in the Kekchi cotton of Guatemala. Some 

 varieties do not have true axillary branches, but develop limbs from 

 the extra-axillary buds of the main stem, the production of flowers 

 being deferred until fertile branches can be produced on the limbs. 

 This is sometimes the case with the Pachon cotton of western Guate- 

 mala and Avith the Rabinal cotton of the central plateau region. In 

 an experiment with the Pachon cotton at Lanham, Md., no axillary 

 limbs were produced, each node bearing only an extra-axillary limb. 

 In another experiment at Trece Aguas, Alta Vera Paz, Guatemala, 

 the Pachon cotton showed nearly the normal habit of the Upland 

 type of cotton, bearing most of its crop directly on fertile primary 

 branches, sending out small primary limbs only in the latter part of 

 the season. 



In the Old World cottons {Gossypkim herhaceum) and the Sea 

 Island cottons it is not usual for the plants to develop true axillary 

 limbs to functional size. If the other branches are injured or stunted, 

 the axillary limbs may push out a few leaves. 



In the Egyptian cotton, also, there is a very general tendency to 

 develop vegetative limbs as well as the fertile branches from extra- 

 axillary buds. The axillary buds usually remain dormant unless 

 an injury or other abnormal condition forces them into groAvth. 

 At the base of the main stalk it is often difficult to see that the limbs 

 come from extra-axillary buds, but a little farther up it becomes 

 obvious that both the limbs and the fruiting branches have extra- 

 axillary positions on the same side of the axillary bud. with much 

 regularity. Finally, some varieties of Upland cotton may not form 



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