INTRODUCTION. 



EVERY art and science has a language of technical terms 

 peculiar to itself. With those terms the student must make 

 himself familiarly acquainted at the outset ; and first of all, 

 he will desire to know the names of the objects about which 

 he is to be engaged. 



The names of objects in Natural History are double, that 

 is to say, they are composed of two terms. Thus, we speak 

 of the white-bear, the black-bear, the hen-hawk, the sparrow- 

 hawk ; or, in strictly scientific terms, we have Felis leo, the 

 lion ; Felis tigris, the tiger; Felis catus, the cat ; Canis lupus, 

 the wolf ; Canis vulpes, the fox ; Canis familiar is, the dog, &c. 

 They are always in the Latin form, and consequently the 

 adjective name is placed last. The first is called the generic 

 name ; the second is called the trivial, or specific name. 



These two terms are inseparably associated with every ob- 

 ject of which we treat. It is very important, therefore, to 

 have a clear idea of what is meant by the terms genus and 

 species; and although the most common of all others, they 

 are not the easiest to be clearly understood. The Genus is 

 founded upon some of the minor peculiarities of anatomical 

 structure, such as the number, disposition, or proportions of 

 the teeth, claws, fins, &c., and usually includes several kinds. 

 Thus, the lion, tiger, leopard, cat, &c., agree in the structure 

 of their feet, claws, and teeth, and they belong to the genus 

 Felis ; while the dog, fox, jackall, wolf, &c., have another 

 and a different peculiarity of the feet, claws, and teeth, and 

 are arranged in the genus Canis. 



The species is founded upon less important distinctions, 

 such as colour, size, proportions, sculpture, &c. Thus we 

 have different kinds, or species, of duck, different species of 

 squirrel, different species of monkey, e., varying from each 



