394 



GENERATION. 



nent, are gradually invaded by fibrous tissue, their gelatinous 

 contents disappear, and the intervertebral disks, composed of 

 fibro-cartilaginous structure, remain. These disks are perma- 

 nent between the cervical, the dorsal, and the lumbar ver- 



The first six cervical vertebrae of the embryon of a rabbit, one inch in length. a &, cephalic 

 portion of the notocorde exposed by the removal of the cartilage ; 6, portion of the chorda 

 dorsalis slightly enlarged, which, in this embryon, was situated between the atlas and the 

 occipital bone ; c, odontoid process ; <2, base of the odontoid process ; e, inferior, or second 

 part of the body of the axis ; f, k, enlargements of the chorda dorsalis between the ver- 

 tebrae ; g, cartilage of the lateral portion of the atlas ; A, lateral portion of the axis ; i, , 

 transverse apophyses of the vertebrae. (LITTRB ET ROBIN, IHctionnaire de medecine. 

 Paris, 1873, p. 1041.) 



tebrae ; but they eventually disappear from between the dif- 

 ferent parts of the sacrum and coccyx, as these are consoli- 

 dated, this occurring, in the human subject, at from the ninth 



