THE INSECTIVORES 311 



breastbone, by which the order is at once distinguished from the Carnivora. Ex- 

 ternally, the Insectivores are very generally characterized by their very long and 

 narrow snouts, in which the muzzle is produced considerably in advance of the end 

 of the lower jaw ; while their bodies are covered either with fur, or, more rarely, 

 with a protecting armor of spines. On opening the skull it will be found that the 

 upper surfaces of the lobes of the brain are smooth ; and thereby very different 

 from those of a Carnivore. 



There are other distinctive characteristics of the order, for the proper apprecia- 

 tion of which a knowledge of anatomy is requisite. If, however, the whole of the 

 points mentioned above receive due consideration, there will be but little fear of con- 

 fusing an Insectivore with any other Mammal, except it be a Marsupial. The Mar- 

 supials, however, as will be shown in the sequel, are broadly distinguished by many 

 important characteristics ; while, were it not for the opossums, they would be re- 

 stricted to the Australian region, in which Insectivores are unknown. Moreover, 

 with the exception of the Virginian species, the opossums are confined to South 



SKELETON OF HEDGEHOG. 



America, where Insectivores are absent ; and there is accordingly not much risk of a 

 living Marsupial being mistaken for an Insectivore, or vice versd. In all respects, 

 as is well shown by their small and smooth brains, the Insectivores occupy a very 

 low position in the Mammalian series ; and next to the Marsupials and Monotremes 

 of Australia, they may be regarded as more nearly allied to the original primitive 

 Mammalian stock than any other members of the class now existing. Their nearest 

 relatives are the bats, which, as already mentioned, may be regarded merely as In- 

 sectivores specially modified for a life in the air. It must not, however, be supposed 

 that any living Insectivore can be regarded as the ancestral form of the bats ; such 

 ancestors having totally disappeared ages and ages ago. In other directions indi- 

 cated by extinct types, it is probable that the Insectivores are allied to the lemurs on 

 the one hand ; while on the other, they may have been derived from the Marsupials. 

 The Insectivores are widely scattered over the globe, although 

 absent from the two large regions mentioned above. Some of the 

 most curious forms are found in Madagascar, Africa, and the West Indian islands. 



