372 BIOLOGY. 



face. (See Oken's Ueber die Bedeutung der Schadel- 

 knochen, 1807. Isis, 1817, S. 1204.) 



2114. Several vertebrae are, however, found for the 

 sense of feeling or touch, because it includes all the 

 organs of the trunk. There must be therefore as many 

 vertebrae in the trunk as there are particular organs 

 placed therein. Of these there are three, the respiratory, 

 digestive, and sexual system, or thorax, abdomen, and 

 pelvis. To the thorax belong the neck, the arms, and 

 the entire set of ribs. 5 vertebrae must enter into the 

 composition of the arms, because they have 5 digits 

 and 5 nerves. But the ribs, and consequently also 

 the digits, are determined by branchial vessels, are only 

 repeated branchial arches, whose number in almost 

 the entire class of fishes is 5. There are therefore also 

 5 thoracic or pulmonic vertebrae. Since the larynx con- 

 sists of the 5 original branchial arches, and lies in front 

 of the neck ; so must the 5 superior cervical vertebrae 

 stand in the signification of branchial vertebrae. The 

 odontoid process of the second vertebra must be regarded, 

 from its being separated from it in the foetus, as a 

 particular cervical vertebra. Accordingly, in the Mam- 

 malia there are eight cervical vertebrae. The 3 inferior 

 cervical, and the 2 upper costal or rib-vertebrae, give 

 off through their interspaces the nerves of the arms, and 

 are consequently the brachial vertebrae. The 3 7th rib 

 are thus appended to the 5 proper thoracic vertebrae, 

 which stand in the signification of the pulmonary vertebrae. 

 To these succeed the 5 short ribs which belong to the 

 abdomen; their vertebrae are thus intestinal vertebrae. 

 The succeeding vertebrae belong to the sexual system, 

 and are indeed the 5 lumbar or pedal vertebrae, because 

 they furnish the pedal or foot-nerves, the 5 sacral ver- 

 tebrae being the proper sexual vertebrae. The coccygeal 

 or caudal vertebrae correspond to the cervical vertebrae, 

 and are present for the sake of the sexual branchiae ; 

 usually one and the other is arrested. Thus there are, 



3x5 Respiratory vertebrae. 

 3x5 Sexual vertebrae. 

 1X5 Digestive vertebrae. 



