32 Ewart . — The Influence of Correlation tip on the Size of Leaves. 
the subsequent expansion of the leaf merely involves an increase in their 
size, for the large dimensions shown by the leaves on the shoot defoliated 
in spring were attained owing to a longer continuance of growth, and to 
a larger production of cells during expansion. The absence of any power 
of response in the adult summer leaves is possibly correlated with the fact 
that the power of regenerative bud-development is much less pronounced 
in summer than it is in spring. 
