1914] 



The Ottawa Naturalist. 



49 



understand it, the morphological character of the flowering 

 branch, as modified by dorsiventral development and by dis- 

 harmonic growth in a longitudinal sense as between the upper 

 and lower moieties of the axis, must be comprehended. The 

 flowering branch is sympodial, but this is frequently much 

 masked by displacement due to elongation of the nodal segments. 

 That such elongation occurs is proved by the position of the 

 stipular ridges ' and occasionally by the actual longitudinal 

 renting in twain of the stipular blade, and the distant separa- 

 tion of its two moieties by intercalary growth in the axis. In 



a B c 



Figure 3. (a) The position of the abscission layer in the peduncle of cotton when it 

 is downwardly displaced; (b) the same when, instead of total displacement, the base of 

 the peduncle is elongated; (c) diagram to indicate possible positions of the abscission 

 layer as determined by the elongation of the peduncle base. In (a) and (c) the stipule of 

 the hidden side is indicated by a broken line. (Gossyptum herbaceum) . 



extreme cases of this kind, what appears to be an internode is 

 really a much extended node, in which-eventthe peduncle, which 

 is the chief shoot, will be downwardly displaced as a whole 

 (Figure 3a) (it may be to the lower hmits of the stipular ridge), 

 or its base will be correspondingly drawn out (Figure 3b). If 



* Cook, O. F., (20) has discussed this point, but does not draw any 

 unequivocal conclusion, inclining the view that the flowering branch is 

 monopodial, which myself found it difficult to avoid, until the evidence 

 forthcame. 



