LIFE OF THE LAND 



253 



cannot be cast adrift to hatch and care for themselves; 

 the nest, the burrow, the den must be provided. This is 

 the realm of homes. 



The land animals are also the most intelligent. Birds 

 long ago solved the problem of flight for a body heavier 

 than air, which is now being successfully solved by man 

 after years of effort. Certain animals, like the bee, the 

 ant and the squirrel, have the provident habit of storing 

 up food in the summer against a day of need. Other ani- 

 mals, like the birds, have learned to migrate to a warmer 



A BEAVER DAM. 

 Notice the two beavers on top of the dam. 



clime when winter comes. The beaver is probably the 

 pioneer in hydraulic engineering. When he feels the need 

 of a water reservoir, he builds a dam and makes it. To- 

 day many a swamp in the northern states owes its origin 

 to him. Wonderful indeed is the intelligence of many of 

 the land animals, due in large part to their development 

 amid varied geographical conditions. 



