CHAPTER III. 



OF THE CLASS MAMMALIA. 



7 1 . THE class MAMMALIA is composed of Man, and of all the 

 animals which resemble him in the most important points of their 

 organisation. It is naturally placed at the head of the Animal 

 Kingdom, because composed of the beings, whose movements are 

 the most varied, whose sensations are the most delicate, whose 

 faculties are the most numerous, and whose intelligence is the 

 most developed ; and it interests us more than any other, as it 

 furnishes us with the animals which are most useful, whether 

 as serving for our nourishment and for labour, or as supplying the 

 materials of our manufactures. 



72. It is in general easy to distinguish a Mammal, at the 

 first glance, from a Bird, a Reptile, a Fish, or any other animal ; 

 by the single observation of its external form, and the nature of 

 its covering : for the Mammalia are the only vertebrated animals 

 whose bodies are covered with hair; and their general form 

 usually differs but little from that of the species, which we have 

 continually before us, and which we naturally take as the types 



FIG. 45. PORPOISK. 



of this group. But sometimes they are not recognised by so slight 

 an examination ; for there are some, whose skin is completely 



