INTRODUCTION. 



The Animal Kingdom is divided into many great classes, the first of NS'hicli 

 is known by the term of Mammalia, and comprises a vast nnniber of animals 

 of different forms, natui'es, and habits. In this little volume will be fomid 

 a short history of the more prominent memljers of this class, whose charac- 

 teristics are briefly and simply as follows. 



The term Mammalia is derived from the Latin word "manmia," or breast, 

 and is appropriated to these creatures because duiing their earliest days of 

 life they obtain their nourishment from their mother's breast. They all 

 possess a skeleton, composed of firm, solid bones ; the blood is red and 

 warm, propelled by means of a heart with four cavities, and they breathe 

 by means of lungs, and not by gills. 



The skin of these creatures is ahnost always furnished with hairs, more 

 or less plentiful and more or less strong. In most instances the hairs are 

 thickly planted and moderately fine, while in some species, such as the 

 Rabbit and the Chinchilla, they are singularly soft and downy. Sometimes the 

 hairs are stiff and coarse, as in the Swine, and are then tenned bristles, 

 and in some instances they become enormously thick and strong, as in the 

 Hedgehog, the Porcupine, and the Echidna, and are then called spines. 



