34 



THE GNAWING ANIMALS. — ORDER RODENTIA. 



Animals of this character form a very natural group; 

 the squirrel, mouse, beaver, no one will mistake them, or 

 confound them with other creatures. One important char- 

 acteristic they have, which gives them the name rodents or 

 gnawers, it is seen in their chisel-like front teeth. The four 

 front teeth, which in cats, dogs, and most other animals are 

 quite small, and apparently of little use, are in the rodents 

 developed into important organs. The beaver not only 

 finds his food by gnawing, but his gnawers are tools, by 

 which he builds his house and home. 



This is a very large order, and can here only be viewed 

 in a general way. The familiar mouse and squirrel sug- 

 gest to us examples. A glance at recorded facts shows us 

 that the rodents are distributed pretty completely over the 

 world. Many groups are confined to certain localities ; 

 for example, no less than twelve genera are exclusively 

 African. 



Of the order of rodents there are over 800 living species 

 known. The squirrels alone have one hundred and eighty- 



