THE SIGNIFICANCE OF LEA VES. 



795 



no two trees are exactly alike. There are specific as well as ge- 

 neric differences which are strongly marked. One tree leads a 

 rugged, wild, and struggling life ; another an easy, luxurious life. 

 The rough and fuzzy leaf of the slippery elm, the silky leaf of 

 'the beech, the shiny leaf of the gray birch, these are all widely 

 different; but there are also distinct differences between the 

 leaves of the several kinds of birches, elms, and maples. 



Still, there are puzzling similarities, and one is often compelled 

 to study minute details in order to make sure of a particular 

 species. The catalpa leaf is mentioned as that having the simplest 

 form. It is without divisions, and has an entire and unbroken 

 edge. The magnolia leaf, which is oval, might as well have been 



White Oak. 



taken as the type ; and there are others equally simple. The 

 most complex form of leaf is exemplified in that of the horse- 

 chestnut. 



A very interesting exercise may he had in tracing the differ- 

 ences in the shapes of the leaves of trees of the same family, 



