ZOOGENY. 371 



the ribs are smaller, as in the ventral ribs, and anchylosed 

 with the body, as in the cervical vertebrae, where they 

 are represented by the perforated transverse processes, 

 and in the lumbar vertebrae they disappear entirely. 



2112. The formation of the cervical vertebrae, where 

 the ribs have been impacted or interposed between the 

 body and spinous processes, is continued into the cranial 

 vertebrae. These are only expanded cervical vertebrae. 

 At the base of the skull four vertebral bodies lie in a 

 series one behind the other; the body of the occipital 

 bone, the two bodies of the sphenoid, and the vomer. 

 Upon the sides of each of these bodies are situated alar 

 processes, which correspond to the transverse processes 

 of the cervical vertebrae, or to the ribs ; e. g. the articular 

 heads or condyles of the occipital bone, the alae majores 

 and minores of the sphenoids, and the two sides or lateral 

 surfaces of the vomer. Behind these are placed the two 

 broad cranial bones, which correspond to the spinous 

 processes ; as the occipital ridge or crest, the parietal, 

 frontal and nasal bones. The occipital vertebra consists 

 of the body, the two condyles and the occipital crest. 

 The parietal vertebra consists of the body of the pos- 

 terior sphenoid, the alae majores, and the parietal bones. 

 The frontal vertebra consists of the body of the anterior 

 sphenoid, the orbitar wings or alae, and the two frontal 

 bones. The nasal vertebra consists of the vomer, the 

 ethmoid and the two nasal bones. The occipital vertebra 

 is the auditory vertebra ; it incloses the auditory bones 

 and the cerebellum, which gives off the nerves of hearing. 

 The parietal vertebra is the lingual vertebra ; the maxillary 

 and lingual nerves passing through its alae majores. The 

 frontal vertebra is that belonging to the eye; through 

 the orbitar plates or wings the optic nerves pursue their 

 course, and it environs the cerebrum, from which these 

 nerves originate. The nasal vertebra contains the 

 olfactory nerves. 



2113. Each cranial sense has thus only one vertebra, 

 and the skull will consequently be formed of four vertebrae, 

 whereof three appertain to the cranium, one unto the 



