6 THE ARTISTIC ANATOMY OF ANIMALS 



more numerous than the dorsal. These latter are almost 

 always joined to one another by a fusion of their spinous 

 processes ; the two or three last vertebrse are similarly 

 united to the iliac bones, between which they are fixed. The 

 dorsal vertebrae thus form one piece, which gives solidity to 

 the trunk, and provides a base of support to the wings, 

 for the movements of flying. There are, so to speak, no 

 lumbar vertebree, the bones of that region, which cannot be 

 differentiated from the sacrum, having coalesced with the 

 bones of the pelvis. 



Vertebra. 



In reptiles, the relation between the number of the cervical 

 vertebrae and that of the dorsal is very variable ; some 

 serpents are devoid of cervical vertebrae, having only dorsal 

 ones— that is, vertebrae carrying well-developed ribs. 



Vertebra. 



Regarding the direction of the vertebral column in animals, 

 in which the trunk is not vertical, it is evident that the 

 spinous processes point upward, and that in comparing them 

 with those of man the}' must be arranged so that the superior 

 surface of the human vertebra will correspond to the anterior 



