Introduction. 



Trees are among the most familiar objects in Nature, and 

 among the most easily observed and studied ; yet how few 

 people know one from another or have an intelligent under- 

 standing of their life history ! Again, they are among the 

 most important, in their widely different fields of usefulness, 

 furnishing as they do, wood for building, tools, implements, 

 the manifold kinds of construction, and for fuel ; fruits, fibres, 

 resins, gums, drugs and a host of other useful products ; shade 

 and seclusion ; ornaments for our parks, lawns and highways, 

 while our forests, too long neglected, are coming to be recog- 

 nised, after years of education of the people, as having an all- 

 important relationship to the flow of streams by conserving the 

 rainfall and distributing it normally and gradually, thus natur- 

 ally regulating our water-supply. Anything that brings trees 

 more closely to our attention, and that makes us realise their 

 great importance is of distinct value as an educational agent. 



The greater size of trees as compared with shrubs and herbs 

 tends to make them regarded by many as a group of objects 

 essentially different from other plants, so much so that we fre- 

 quently read statements concerning "Trees, shrubs and 

 plants." And yet a tree is not, except in size, so very different 

 in its essential structure from its humbler relatives of the 

 plant community ; it has roots, a stem, leaves, flowers, fruit 

 and seed, as they have ; the fact that all trees bear flowers of 

 one kind or another is perhaps not so generally appreciated as 

 its possession of the other parts mentioned, due, doubtless, to 

 the flowers of many of them being insignificant in size, unim- 



