loosely by botanical writers, and hence have lost to a certain extent their definiteness. 

 That such of those as are used in the present work may be understood in their strict sense, 

 as intended, a little explanation is necessary. We say of a leaf -margin that it is " serrate " 

 (from L. serra, a saw) when it is toothed with sharply- pointed teeth directed forward, 

 i. e. } towards the tip of the leaf. It is " crenate " (from L. crena, a notch) when the 

 teeth are rounded at apex and directed outward rather than forward, i. e,, the margin is 

 scalloped. Forms intermediate between the above are spoken of as " crenate-serrate." The 

 margin is " dentate " when the teeth are distinctly pointed and directed outward, from a 

 rather wide base. Intermediate forms may be crenate-dentate, or may be " serrate-dentate." 

 We trust further definitions may be understood by reference to the glossary. 



It must not be understood that this Leaf Key is intended to take the place of more 

 extensive publications on our trees, but rather to supplement them to enable one to 

 have in compact and systematic form an aid in the identification of trees by a study of 

 their leaf characters. 



LOWVILLE, N. Y., July 15, 1910. 



