PKEFACE 



So much has been written popularly and in a scientific way on 

 trees that no book on the subject would be warranted unless it 

 was designed to meet a decided need. At present there is no 

 general work upon American trees which combines illustrations 

 of the individual forms with keys for their identification based 

 upon winter characters. The forester and lumberman, however, 

 are more called upon to distinguish trees in winter when leaves 

 and flowers are fallen than in summer. Trees, as the most con- 

 spicuous elements in the winter landscape, must also appeal to the 

 student of out door life. The interest shown by classes of school 

 teachers in the Summer School in identifying specimens of twigs 

 collected the previous winter indicated that the winter study of 

 trees can be taken up with enthusiasm by teachers in their schools. 

 In our experience, the winter identification of trees has proven to 

 students one of the most interesting subjects of their course. It is 

 of decided value for its training in the power of accurate obser- 

 vation. The work comes at a time when material for natural 

 history study seems scanty and might therefore be used to bridge 

 over the period between fall and spring which are unfortunately 

 considered by many the only seasons when study of out door life 

 is possible in the schools. A tree in winter is far from being 

 the characterless object many believe. Freed from its covering 

 of leaves, the skeleton of the tree is revealed and with the method 

 of branching thus clearly discernible, the species may generally 

 be more readily identified at a distance than in its summer garb. 

 There are many forms, moreover, that are difficult to distinguish 

 from summer features alone but which in winter have twig, bud 

 or other characters which make their separation comparatively 

 easy. It is believed that the combination of keys, text, and illus- 

 trations from photographs will furnish the assistance which the 

 current texts fail to supply and render the identification of our 

 common trees in winter a relatively simple task. 



The text with keys is an outgrowth of outlines that one of the 

 authors has developed and used with various modifications for 

 the last four years in his college classes in Botany and Forestry. 



