30 MAMMALIAN GALLERY. 



by some with the Lemurs, by others with the Insectivores, but 

 differs sufficiently from both to be considered apart. It contains the 

 so-called Flying Lemurs of Malaysia and the Philippines, animals 

 of about the size of a cat, with a lateral extension of the skin of 

 the body, supported by the four limbs and tail, and forming a sort 

 of parachute. By the help of this parachute, the Galeopitheci 

 can float through the air for considerable distances from tree to tree, 

 but their flying leaps are always in a descending direction, as in 

 Flying Squirrels and Flying Lizards, and not as in Bats, which 

 have the power of flapping their wings and rising and falling in 

 the air at their pleasure. Galeopithecus lives exclusively on vege- 

 table food. Two specimens, one of which has the parachute 

 opened, are exhibited. 



Order VI. RODENTIA, OR GNAWING MAMMALS. 



(Cases 27-32.) 



The Rodentia, or Gnawing Animals, comprise the Squirrels, 

 Rats, Hares, &c., and form by far the largest order of Mammals, 

 containing over 900 distinct species, a number more than double 

 that of the next largest, the Chiroptera. As a whole, the Rodents 

 are distinguished by their small size, nocturnal habits, and vege- 

 tarian diet, all of them living mainly on fruits, leaves, nuts, and 

 other similar food, although many of the species will occasionally 

 eat eggs, birds, fish, or other animal food. Their peculiar denti- 

 tion, by which they are distinguished from other Mammals, is 

 described on p. 83. 



With regard to their geographical distribution, they are, next 

 to the Chiroptera, the most widely spread of all Orders, extending 

 over the whole world, with the exception of the more remote 

 Pacific islands, to which they have never had means of access. 

 Many of the species are arboreal, like the Squirrels, or aquatic^ like 

 the Water- Voles and Musquashes ; but the great majority are bur- 

 rowing and terrestrial animals, which only come forth by night to 

 seek their food, on which account, although so numerous, they are 

 but little seen by ordinary observers. 



The Order is divided into those with only one pair of incisor 

 teeth in the upper jaw, and those with two. The first of these 



