OR OSSEOUS SYSTEM. 



FIG. 53. 



flat portions of the bodies of the vertebra remain long, se- 

 parate, as detached pieces, in these animals. The cervical 

 vertebrae are sometimes all anchylosed together, and in the 

 herbivorous cetacea, where the neck is longer and more 

 moveable, ah 1 the cervical vertebrse are larger, and detached 

 from each other. In the preserved skeletons of the laman- 

 tine there are but six cervical vertebrse. The spinous pro- 

 cesses extending upwards from the dorsal and coccygeal 

 vertebrae (h, h, h } ) are here long and strong, and often sup- 

 port a cartilaginous hunch upon the back, in form of a ver- 

 tical fin (i } ) and inferior spinous processes are developed 

 below the coccygeal vertebrae, for the protection of the great 

 blood-vessels. The transverse processes are also long, for 

 the attachment of powerful muscles, and they limit the ex- 

 tent of lateral motion in the column. Many of the last 

 coccygeal vertebrae (u y ) have only their round bodies developed, 

 and admit of free and extensive motion in every direction. 

 The anterior part of the thorax is the most fixed, to give at- 

 tachment to the powerful muscles of the neck and of the arms, 

 and the ribs are there attached both to the bodies and to 

 the transverse processes of the vertebrae ; but on the pos- 

 terior part of the thorax, where there is greater freedom of 

 motion, the ribs are attached only to the ends of the long 

 transverse processes. There are no bones extending into 

 the fin-like cartilaginous hunch (i,) upon the back, nor into 

 the lateral cartilaginous expansions of the tail (v,) as we find 

 in these parts in fishes. The sternum is very short, and 

 confined to the anterior ribs, and the sternal ribs are gene- 

 rally ossified, as in many other quadrupeds, and in birds, and 

 in many reptiles. Although there are no legs, we always 



PART I. H 



