6 HORSE AND MAN. 



animal consists of a skull followed by a series of 

 vertebras. 



Limbs are only appendages ; many vertebrates, 

 such as the generality of the snake tribe, not possess- 

 ing them. Even ribs are not necessary for existence, 

 as we see is the case with the frogs, in which animals 

 the ribs are totally absent. So, following the order 

 of nature, we will first take the skull and vertebras. 



A represents the skull itself, b is the eye-hole 

 {orbit), c is the upper jaw (superior maxillary), d are 

 the nasal bones — i.e. the bones of the nose, e is the 

 lower jaw (inferior maxillary), e is the ear-hole (audi- 

 tory foramen). 



As to the teeth, the reader will observe that there 

 is a considerable gap between the canine teeth, or 

 1 tusks,' and the molars, or grinders. Were it not for 

 this gap, the bit could not be inserted in the mouth, 

 and man would lose his most powerful means of 

 guiding the animal. 



B comprises the neck bones (nuchal or cervical 

 vertebras). These are always seven in number in the 

 mammalia, no matter what the length of the neck 

 may be. Whether the neck may belong to the giraffe, 

 which feeds on tree-leaves eighteen feet from the 

 ground, or whether it be the property of the whale, 

 which has no perceptible neck at all, the nuchal 

 vertebra? are seven in number. In the former animal 



