332 MAMMALS 



fifth is free and forms a sort of hook, or claw (Fig. 230). 

 The membrane covering the fingers and forming the wing 

 is nearly or quite devoid of hair. The bodies of bats are so 

 much like those of mice, in general, that the Germans call 

 them " flitting mice." The eyes are small, but the ears are 

 large, and the sense of touch is acute. The hind legs are 

 small and weak. 



The common bats are nocturnal in habits. During the 

 day they remain hidden in a hollow tree, cave, or dark 

 recess, coming forth to seek their prey at twilight and night. 

 Those bats that live in cold climates and do not migrate, 

 hibernate during the winter. 



The fruit-eating bats found in India, Ceylon, the Malay 

 Archipelago, and eastern Australia are of large size and 

 have foxlike heads with large eyes apd are diurnal in 

 habits. They feed almost exclusively-, upon fruits. The 

 fruit bats or flying foxes of Ceylon often have a wing ex- 

 panse of forty inches. They frequently live in colonies of 

 fifty or more individuals. 



In the valleys of the Amazon and in other parts of South 

 America are found the true vampire bats. These actually 

 suck the blood of wild animals and in some localities cause 

 considerable injury to domestic animals. Moreover, the 

 vampires often bite human beings on the nose or feet while 

 asleep at night. These bats are all small, their bodies 

 measuring less than four inches in length. 



The First Mammals (Primates) 



The Primates are characterized by having prehensile 

 limbs because the pollex, or thumb and the hallux, or great toe 

 are opposable to the other digits. There are usually five 



