506 



MacDougal : Some Correlations of Leaves 



on the first internode, but their length, width and thickness was 

 such as to give the exaggerated extension noted above when com- 

 pared to correspondent structures on normal branches. Further- 

 more, three pairs of stipules were present on normal twigs and ten 



Fig. 2. A, Acer ; normal and defoliated branches. The dotted line shows the 

 bases of new growth. H, Frunus ; transverse section of normal stipule. (Z, Primus ; 

 transverse section of stipule of delaminated leaf. B and C are drawn to same scale. 



pairs on those which had been defoliated. It is thus to be seen 

 that twigs which had been deprived of the laminar portions of the 

 leaves made such development and retention of the stipules that 

 they were able to expose about fifteen or sixteen times as much 

 stipular surface as normal correspondent branches. 



The increase of the stipular surface consequent upon the re- 

 moval of the laminae is not unknown, and Goebel notes that simi- 



