Photograph by Howard Taylor Middleton 



HEREDITARY ENEMIES ! A CAT WATCHING 



A GRAY SQUIRREL 



At one time the gray squirrel was so abund- 

 ant as to make ruinous inroads on the corn 

 and wheat crops of our pioneers. In Ohio, a 

 hundred years ago, there was a law requiring 

 each free white man to deliver ioo squirrel 

 scalps every year or pay a penalty of $3. To- 

 day the gray squirrel needs legal protection to 

 prevent its extermination. 



four-footed habitants. Many modifica- 

 tions of parts and organs of the various 

 species have been necessary to adapt the 



small mammals to specialized modes of 

 life. 



ANIMALS 



AT LKARNKI) T( 



I N 



This is strikingly illustrated in the case 

 of those true rodents, the. pocket-gophers, 

 which apparently found competition on 

 the surface of the ground so acute that 

 they took the unoccupied territory below 

 the surface, where they live as miners 

 and tunnel from place to place in search 

 of edihle roots, with an occasional stealthy 

 excursion ahove ground to seize some of 

 the food available there. 



Another excellent illustration is fur- 

 nished by the moles, which, leaving the 

 numerous closely related species — the 

 shrews — to feed upon insects above 

 ground, have descended and, like the 

 pocket-gophers, live in tunnels which they 

 make in the pursuit of earthworms and 

 insects below the surface ; like the go- 

 phers, they, too, make occasional excur- 

 sions above ground in search of food. 



The mink and the muskrat, represent- 

 ing the carnivores and rodents, have 

 rivals for their food supply on land and 

 have become amphibious, being as much 

 at home in the water as on shore, one 

 feeding on fish and flesh and the other on 

 aquatic vegetation. Certain forms of the 

 squirrel tribe are heavy-bodied and live 

 in underground burrows, while other 

 more slender and graceful species make 

 their homes in the tree-tops. 



A DEPARTURE FOR EVERY NEED 



Another member of this group, the fly- 

 ing-squirrel, has developed an extension 

 of the skin uniting the front and hind 

 legs, so it may glide freely from tree to 

 tree. The bats have gone still further, 

 and the skin uniting their lengthened 

 front and hind limbs and long finger 

 bones forms broad wings which lend 

 them powers of flight scarcely equaled by 

 those of birds. 



The gophers, pocket-mice, chipmunks, 

 and others are provided with little cheek 

 pouches in the skin on each side of the 

 mouth, in which they may carry food 

 home to their store-rooms and other hid- 

 ing places. 



The hares have developed long legs for 

 running on open plains, and the weasels 

 have long, slender bodies and an exceed- 



372* 



