vi PREFACE TO THE FIRESIDE EDITION 



This work was designed to afford the general reader, the parent, 

 the teacher, and also young people an opportunity to obtain a speak- 

 ing acquaintance, on a scientific basis, with the best representa- 

 tives of the living vertebrate animal forms of North America. 

 The great multiplication of species and geographic races that has 

 taken place during the last few years renders necessary this new 

 edition of the original work. A glance at the number of species 

 and races in the Order of Gnawing Animals is sufficient to convince 

 the average reader of the necessity of a general view, and the 

 impossibility of a complete acquaintance with even our own quad- 

 rupeds. 



The time was when a diligent student could at least know every 

 mammalian species by name; but that time went by long ago. 

 The gulf that now is fixed between the zoological investigators and 

 the general zoologist is becoming wider and deeper day by day. 

 Consider the possibilities for mastering the identity of 784 species 

 and 453 subspecies of the Order of Gnawing Animals (Rodents) . 



We must accept the fact that in the scientific determination 

 of the precise status of a fauna, subspecies are necessary, even 

 though it is not possible for the layman to recognize them. I am 

 convinced that to-day a great many subspecies exist on very nar- 

 row grounds; but we are concerned with only a very few of them. 

 Let us become acquainted with the important forms, and the types 

 of the groups that are most worth knowing. 



In reckoning up numbers of species and subspecies I have 

 accepted Dr. D. G. Elliot's "Check List of North American Mam- 

 mals" (1905) as the best authority, and quite , suflScient for the 

 purposes of this work, even though a few forms have been added 

 to our fauna since its publication. For the classification of the 

 mammals of the world, living and extinct, the highest authority 

 and literally the last word, is the "Age of Mammals," by Professor 

 Henry Fairfield Osborn. The scientific student is advised to ac- 

 cept and follow his scheme of classification. 



