220 ELEMENTARY ANATOMY, [LESS. 



diapophyses T ) and ribs, and the other made up of capitular 

 processes (or parapophyses 2 ) and ribs. 



FIG. 188. Six TRUNK-VERTEBRAE OF THE FISH Polypterus. 



p, series of inferior ribs, from the roots of which the seffes of superior ribs (s) 

 diverges and extends outwards and upwards. 



In man, as in most Vertebrates, the superimposed pairs of 

 these two series of parts are completely united, except at their 

 root, but a wider examination shows their probable essential 

 duplicity, and makes visible relations and a significance in 

 the transverse process of his thoracic and cervical vertebrae, 

 which no study of anthropotomy, however patient and minute, 

 could of itself reveal. 



10. Still less would it, from such study, be possible to divine 

 the nature of that hardly noticeable ridge which extends 

 along the middle of the body of his axis vertebra on its 

 ventral aspect ; yet that ridge is really a rudiment of a system 

 of parts hardly less conspicuous and important in the verte- 

 brate skeleton than the two series already noticed. 



It may be remembered, however, that in some Mammals 

 (e.{r. the Ornithorhynchus) a median spinous process projects 

 downwards from beneath the centrum of the cervical verte- 

 bras ; as also the great development of such processes (hypa- 

 pophyses) in poisonous Serpents, and their extension through 

 the greater part of the whole vertebral column. 



We have also seen how such median structures are directly 

 in series with and answer to processes descending in pairs, 

 or to forked processes, which start from a common bony 

 stalk ; also that arches (chevron bones) of similar nature may 

 attain a very large size, as in the tails of Whales and Por- 

 poises. 



Finally, we have seen that a still more important and con- 

 spicuous part may be played by the same skeletal elements, 

 as in some Fishes (e.g. the Sole), where elongated arches and 



1 From <3<a, through. a riapu, beside. 



