INTRODUCTION. 



IN the very numerous forms of life with which we meet we cannot 

 help noticing that there are all degrees of likeness and difference. We 

 believe that all these forms are in some sense related to each other, and 

 the closer the similarity the closer we consider this relation to be. When 

 such likeness is as exact as we are accustomed to find in Nature, we say 

 that the forms compared are of the same kind or Species, and we mark 

 them by the same name, noticing that the individuals reproduced from 

 these continue equally similar to each other and to the parent forms. 

 A number of species plainly related to each other, yet not the same, form 

 a Genus, the plural of this Latin word being Genera. Thus all our 

 Maples belong to one Genus, though there are five or six species ; and we 

 have at least a dozen distinct kinds of Willows, all belonging to the same 

 group or Genus in the same way. Similar Genera again are grouped into 

 Families, or Orders, and these again into higher and higher classes, upon 

 which at present we need not dwell. 



Such a classification . would, of course, be impossible without some 

 accurate system of naming, and the method introduced by the great 

 botanist, Linnreus, about one hundred and fifty years ago, is now com- 

 monly used everywhere among students of Nature. In this system every 

 Genus has a distinctive name, and this name, with a modifying word 

 added, may become the full name of any species in that Genus. Thus, 

 Acer is the name of the Maple Genus, while Acer rubrum, Acer sacchari- 

 num and Acer dasycarpum are three distinct kinds of trees within this 

 Genus. To some it seems a pity that these names should be in Latin, 

 but they have the corresponding advantages of being the same in all 

 languages, and of having an exactness that would not be possible with 

 e very-day words. Thus, Acer rubrum will be known by this title 

 wherever it is mentioned by botanists ; while " Red Maple " or " Soft 

 Maple " might easily be applied to several trees, even within the same 



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