86 STRUCTURE OF THE VERTEBRATES 



to the presence of the lateral incisors in addition to the median, 

 and a history which indicates early separation from the typical 

 rodent stock. The rabbit is a favorite laboratory animal for 

 dissection. 



Order Cheiroptera. The bats, which form this order, are fly- 

 ing mammals. The name literally means ''hand wing", the digits 

 being enormously elongated with a leathery membrane stretched 

 between them. Their dentition and internal anatomy show them 

 to be closely related to the insectivores. The existing members- 



Rabbit (Rodentia) 



Fig. 34. Rodentia. Capybara is the largest living rodent. The rabbit is 



more technically placed in a different order, Lagomorpha. The porcupine 



is a true rodent with long ectodermal spines. 



are mostly insect eaters, although some are fruit eating, and a 

 few (the vampire bats) cut the skin of other animals and drink 

 the blood. This genus of South American bats has sharp canines 

 and incisors, a gullet which permits only liquid food, and an 

 almost straight digestive tract forming a "stomach-intestine". 

 The distribution of the order is world wide, their flying habits 

 having permitted them to invade Australia and other insular 

 regions. 



Order Edentata. The edentates are not all entirely toothless, 

 a few having small teeth, and some have teeth in the young 



