2 
od 
08 BATTLES OF PLANTS IN THE WORLD 
driven out or have not been able to enter. Those 
which could take on these forms of the cacti, or of the 
yuccas, etc., bore trunks with a tew hard-skinned 
leaves at the tops, survived, and now find these con- 
ditions quite congenial to them. 
Hedgerow and roadside societies. Not every one of 
you can go to the desert to see the desert societies, 

Fic. 307. Desert society, chiefly yucca, 
or to see the arctic or tropical societies. You must 
be content with pictures of them. But nearly every 
one can see plant societies near at hand that are 
interesting if looked at in the right way. Some of 
you, in large cities, perhaps do not often see hedge 

