18J: 



Charles Eussell Barcleen 



vertebra the cartilaginous anlage is very transitory, in the first vertebree 

 it forms the anterior portion of the arch of the atlas. Weiss describes 

 two bilaterally placed centers of chondrification in the hypochordal 

 brace of the atlas in the white rat. No cartilage is fonnd in the more 

 distal hvpochordal Ijraces. In man a hypochordal brace becomes well 



Corpus 

 sphenoidale 

 (posterior portion) 



Chorda dorsalis 

 Os occipitale pars basilaris 

 Atlas 

 arcus ventralis 



Costa I 



Vertebra thoracalis 



Pedicle' 

 Processus articularis anterior/ 



Lamina 



Fig. 2. — Postero-iuedial view of the model represented in Fig. 1. The 

 anterior extremity of the base of the occipital and the posterior part of the 

 body of the sphenoid are also shown. Between the posterior part of the base 

 of the occipital and the epistropheus the intervening dense tissue has in part 

 been removed so as to reveal the ventral arch of the atlas. The interver- 

 tebral discs are omitted between the fourth and fifth, fifth and sixth cervical, 

 and between the seventh cervical and first thoracic vertebra?. 



