512 MacDouGAL: SOME CORRELATIONS OF LEAVES 
such manner as vastly to increase their capacity for photosynthe- 
sis and transpiration. 
VI. The loss of the lamina acts as a stimulus which induces a 
development and differentiation of spongy parenchymatous and 
other tissues in the stipule, and the formation of chlorophyl. 
VII. The lateral buds of Acer on internodes formed during the 
previous season were awakened by defoliation of the extending 
apical portion. ) 
VIII. The period of activity of the vegetative point of the 
terminal portion of a woody branch is not lengthened as a result 
of defoliation. 
IX. The total length of the newly formed portion of the 
branches defoliated during growth was thirty to sixty per cent. 
less than that of normal branches occupying the same relative 
positions on the shoot. 
X. The number of internodes developed on defoliated branches 
was greater than in the normal. 
XI. The defoliated internodes were of a diameter not greater, 
sometimes less than the normal, and had accomplished less perfect 
differentiation. 
XII. Branches compelled to accomplish growth in a defoliated 
condition generally are found to be in a state of hypoplasia, the 
undeveloped and imperfectly differentiated condition of the tissues 
being due to the lack of correlative stimuli. 
New York BOTANICAL GARDEN. 
