XVni THE MAMMALS OF INDIA. 



recurved horny spines, used to scrape the last fragments of flesh 

 off bones. 



The tongue is supported by a bone called the Hyoid bone, the 

 anterior horns of which, small in Man, are greatly developed in most 

 Mammals. The velmn palati, which protects the communication 

 between the mouth and posterior nasal cavity is only found in this 

 class ; and the trachea, which lies in front of the oesophagus, is 

 protected by the epiglottis. The oesophagus leads straight to the 

 stomach from the end of the pharynx, and is of moderate width, 

 but dilatable. The stomach presents great varieties of form. In 

 most, it is a simple bag of varied shape and size ; in some, divided 

 into compartments by constrictions, but without any apparent 

 difference of structure. In one tribe, however, the Ruminants, 

 it is a truly compound structure, consisting of several distinct cavities 

 differing both in size, structure and functions. The small intestines 

 vary little, but the large intestines are very variable in size, and 

 the division between them is in many marked by an appendage 

 called the ccvcum, sometimes double, and in certain animals of great 

 size. In some, especially the Plantigrade Carnivora and Cetacea, it 

 is entirely absent. 



The liver is generally of large size, and is usually divided into 

 several lobes. In most it is furnished with a gall-bladder. The 

 pancreas and spleen are always present. 



The inferior muscular energy of Mammals compared with that of 

 Birds is accompanied by an inferior amount of respiration, and on 

 this account the heat of animals is much less, rarely exceeding 

 100° of Fahrenheit. The organs of respiration and circulation 

 differ little throughout the class from those of Man. The heart 

 consists of four cavities ; and the lungs, which are always in pairs, 

 are completely inclosed, and have no communication with air-cells 

 as in Birds. These viscera are separated from those of the abdomen 

 by the diaphragm, a muscular partition, which is one of the chief 

 agents in respiration. The lungs are more porous and spongy in 

 texture than in Birds. Variations in the structure of the heart and 

 circulating system are only met with in Cetaceous animals, which 

 have some interesting peculiarities dependent on their remaining 



