394 Journal oj Agricultural Research voi. ui. no. s 



terminal positions and to arise from intermediate points. Examination 

 of such cases at first suggested the idea that the floral bud might belong 

 morphologically to the next internode below. In this view the pedicel 

 would be merely coalesced wth the supporting internode, instead of 

 being produced from it. The branch morphology of the cotton plant is 

 unusually complicated on account of the dimorphism of the branches 

 and the extra-axillary position of the floral buds and of the buds that 

 give rise to the fruiting branches.' 



The assignment of the floral bud to the internode below seems to be 

 forbidden by the fact that when the base of the pedicel becomes decurrent 

 upon the supporting internode the stipule that subtends the pedicel and 

 the stipular rim that incloses the base of the pedicel also become elongated 

 and decurrent along the side of the internode. Thus, instead of merely 

 a lower insertion of the flower bud, the whole internode is modified, and 

 the nature of the modification makes it clear that the floral bud is borne 

 normally above the stipular rim. 



Though other families of plants aflford instances where flower stalks or 

 floral branches remain united with the basal portion of the next internode, 

 it is very difficult to believe that an adnate or coalesced pedicel would 

 be able to surmount the stipular rim and climb, so to speak, into the axil 

 of the leaf of the internode with which it had become coalesced. In rare 

 cases the pedicel of a cotton boll is joined to the internode above, but the 

 result is clearly abnormal, and lends no support to the theory of coales- 

 cence of pedicels and internodes as a normal condition. (See PI. LX.) A 

 pedicel that is united with an internode is usually longer than the normal 

 pedicels, while the internode is shorter than the others and is turned from 

 its normal position to follow the direction of the pedicel to which it is 

 attached. There is no tendency in these adherent pedicels to form an 

 angle or a joint at the end of the internode, as might be expected if the 

 theory of coalescence were correct. 



The presence of a flower bud on the basal internodeof fruiting branches 

 offers another difficulty under the theory of coalescence. If it were 

 assumed that each floral bud belongs, not to the supporting internode, 

 but to the one lower down, it would necessarily follow that the floral bud 

 of the basal joint of a fruiting branch could not belong morphologically 

 to the fruiting branch at all, but must be assigned to the main stalk or 

 the vegetative branch from which the fruiting branch is producd. This 

 supposition would add new elements of complexity to the structural 

 morphology of the cotton plant, already sufficiently complicated. 



BRACHYSM ACCOMPANIED BY FASCIATION AND ADHESION 



Further reasons for looking upon brachysm as a failure of normal 

 differentiation of parts are found in the other abnormalities of the 



' Cook. O. V. Morphology d cotton branches. In U. S. Dept. .A.gr. Bur. Plant Indus. Circ. loo. p. 1 1-16. 

 19U 



