316 AUTUMNAL LEAVES. 



vein which divides the leaf in two, and an irregular 

 series of waved, much-forked veins, branching from 

 it. Running across the course of these principal 

 veins are a second series of smaller ones, and, 

 within these, there is a close network of venules. 



The variations of autumn colouring are shown 

 by the presence upon the same tree of leaves of 

 normal summer green, and pale green, golden 

 green, orange and yellow, with light and golden 

 brown. Contrasting shades of these colours are 

 sometimes shown on the same leaf; but it is more 

 frequently in the differences observable in an 

 aggregation of leaves that the autumn character 

 of the Lombardy Poplar is exhibited. 



The foliage of the White and Black Poplars 

 and the Aspen is distinguishable by very clearly 

 marked characters. The white underside con- 

 trasting strongly as it does with the glossy green 

 upper surface, has given rise to the common name 

 of the first-named of these three Poplars. The 

 general form of the leaf is more or less rounded, 

 but it has a pointed apex, and its margin is 

 broadly waved, or cut into short, rounded lobes. 



