37. 
THE WHITE POPLAR. 
Populus alba. 
PuateE 5, Fie. 4. 
of growth, give an especial character 
to Populus alba. To what we have 
already stated as to the features 
which distinguish this species from 
the one last described, we must 
add that its leaves—which in their more 
/ prominently-lobed form present the most 
ci ready means of distinction between it 
and the ‘grey’ species—are very much subject 
to variation from their normal form. ‘This 
variation does not extend merely to different in- 
dividuals of the species—for, in all plants, different 
