826 



character and entering into the formation of very 

 numerous and diversified sets of organs, which 

 have in reality no alliance with each other 

 except that of mere juxta-position. 



One compartment in Man, exceeding in size 

 all the rest put together, but in the lower Ver- 

 tebrata forming but a very small part of the 

 whole, is obviously merely a continuation of 

 the vertebral canal lodging the most anterior 

 ganglia of the cerebro-spinal axis, which it 

 arches over and defends, at the same time 

 affording passage to the nerves that emanate 

 therefrom, being essentially itself composed of 

 vertebrae, although, in consequence of the 

 preponderating size of the brain over the spinal 

 ganglia behind, considerable distortion is re- 

 quired, a distortion which in human beings is 

 necessarily carried to such an extent that the 

 normal construction of this part of the skeleton 

 is in man almost wholly indistinguishable. As 

 the vertebral column forms the centre and sup- 

 port of the trunk and limbs, so does the cranial 

 portion of the skull sustain various additional 

 apparatus, which may be enumerated as follows. 



1 . The auditory apparatus most frequently en- 

 closed in a special bone, the petrous, and interca- 

 lated among the proper bones of the cranium. 



2. The temporal apparatus, which in man 

 is confused into a single irregular mass that 

 forms part of what the human osteologist calls 

 the temporal bone, but which in the lower Ver- 

 tebrata, such as the Keptilia, consists of several 

 important pieces, which being withdrawn from 

 the composition of the cranial box are employed 

 for the articulation of the lower jaw, and more- 

 over in the osseous Fishes sustain the bones of 

 the gill-covers. (Nos. 12, 13, 23, 26, 27.*) 



* The following table, showing the numbers by 

 which the corresponding bones appertaining to the 

 cephalic portion of the skeleton are indicated in all 

 the figures, is given to facilitate comparison be- 

 tween them. 



OSSEOUS SYSTEM. (Coup. ANAT.) 



3. The pterygo-palatine apparatus repre- 

 sented in the human skeleton by the internal 

 pterygoid processes of the (so-called) sphenoid 

 and the ossa palati. These form the framework 

 of the fauces. ( Nos. 25, 22.) 



4. The olfactory apparatus, into the compo- 

 sition of which enter the (Ethmoid, over which 

 the nerve of smell is more particularly dis- 

 tributed, together with the nasal, the superior 

 maxillary, the vomer, the inferior turbinated 

 bones, and others more remotely connected with 

 the formation of the cavity of the nose. (Nos. 3, 

 20, 16, 18, d.) 



5. The orbito-lachrymal apparatus, or the 

 bones which assist in forming the orbital cavity 

 and lachrymal passages. 



6. The superior maxilla formed of the max- 

 illary and intermaxillary bones. fNos. 18,17.) 



7. The inferior maxilla, which in the lower 

 animals consists of several pieces, to be more 

 fully noticed hereafter. 



Before proceeding to describe the individual 

 bones that enter into the composition of the 

 cranial portion of the skull, in order to lay before 

 the reader the comparative structure of that 

 important portion of the skeleton, it will be 



1 Frontal. 



2 Anterior frontal. 



3 Nasal ( asthmoid, Cuv.) 



4 Posterior frontal. 



5 Inferior occipital. 



6 Sphenoid. 



7 Parietal. 



8 Supra-occipital. 



9 External occipital. 



10 Lateral occipital. 



11 Alar. 



12 Mastoid. 



13 Petro-temporal. 



14 Ingrassial. 



15 (Ethmoid (anterior 



sphenoid, Cuv.) 



16 Vomer. 



17 Intermaxillary. 



18 Maxillary. 

 20 Prsnasal. * 



22 Palatine. 



23 Masto-temporal. 



24 Transverse. 



25 Internal pterygoid. 



26 Zygomatic. 



27 Squamo-temporal. 



28 Opercular. 



29 Styloid. 



30 Prajopercular. 



31 Symplectic. 

 3'2 Subopercular. 



33 Interoaercular. 



34 Dental'. 



35 Supra-angular. 



36 Angular. 



g Suborbital plates. 



Fig 436. 



Skull of the Cod(Gadus Vorhua). 



