656 



SKELETON. 



variable proportionals of the sterno-costo-verte- 

 bral quantities. The connection which exists 

 between the cranial and the facial structures is 

 quite as intimate as the connection which 

 exists between dorsal vertebras and thoracic 

 ribs. In nature, we never find the cranial 

 structures happening independent of the facial 

 apparatus ; but we invariably witness the pre- 

 sence of both, whenever the presence of one 

 is manifested, just as is the case with dorsal 

 vertebrae and the costal apparatus; and there- 

 fore it is that when I shall presently draw 

 comparison between cephalic and thoracic 

 regions of the spinal serial axis, I shall regard 

 the one as a cranio-facial series of osseous 

 quantities, homologous to the other as a 

 costo-vertebral series. 



Before I proceed to compare the cranio- 

 facial apparatus with the thoracic costo-verte- 

 bral apparatus, let me here distinctly state 

 one or two positions, which I shall not engage 

 to define, simply because it would be impos- 

 sible to prove that certain conditions were 

 manifested, which are in fact and nature not 

 manifest. Firstly, 1 do not mean to shew 

 that an equality or quantitative uniformity 

 characterises the cephalic and the thoracic 

 regions of the one spinal series ; nor, secondly, 

 that all species of cephalic apparatus of the 

 four classes are constituted of absolutely 

 equal quantitative structure*, any more than 

 thoracic apparatus are themselves ; nor, 

 thirdly, that the number of cranio-facial seg- 

 ments and the number of costo- vertebral seg- 

 ments correspond in the same spinal axis ; 

 nor, fourthly, that the number of cranio-facial 

 segments correspond in the cephalic apparatus 

 of all animals of the four classes, any more 

 than the thoracic apparatus of the same ani- 

 mals correspond as to the number of spinal 

 costo-vertebral segments. 



The so-called "vertebral theory "appears to 

 me to have played lightly with the serious 

 patience of anatomical science, and to have 

 brought itself into discredit, not because it 

 has proved no one truth in generalisation at 

 all, but because it has striven, while standing 

 upon equivocal and unproven grounds, to de- 

 monstrate that which had existence no where 

 save in the imagination. An ill-defined sha 

 dovvy resemblance was first seen to have ex- 

 istence between cranial and spinal vertebral 

 forms, and in pursuance of this idea has 

 arisen all that vagrant and bizarre imagery 



* Almost all the anatomists of the French and 

 German schools differ in opinion as to the number of 

 modified vertebrae which compose the head, for while 

 some of them limit the number to three, viz. those 

 which enclose the encephalon, others count as many 

 as seven ; and these latter have increased the num- 

 ber by absurdly likening the facial structures to the 

 vertebral forms also. Goethe counts six, three of 

 which comprise the cranium, the other three the 

 face. Oken enumerates four; Spix, three; Cuvier, 

 three ; Geoffrey, seven ; Cams, three (Lehrbuch der 

 Zootomie) ; Meckel, three (Beitrage zur verglei- 

 chenden Anatomic, Band II. S. 74.) ; Bojanus ad- 

 mits four, and Burdach only three. Professor Owen 

 enumerates four in the fish, the reptile, the bird, 

 and the mammal. See " Homologies," &c. 



which has enveloped the first dawn of a great 

 truth in the smoke and mist of that sacrifice 

 and homage which it was thought was due to 

 the inspired genius of him* who first promul- 

 gated it. I shall not here trouble either the 

 reader or myself with a barren discussion 

 about the merits or demerits of the views of 

 those authors who sought to expand this ver- 

 tebral theory beyond its natural limits, or of 

 those who strove to discountenance the theory 

 altogether, rather than to pursue it to the 

 verge of sheer nonsense. My present limits 

 confine me to the observation of nature, and 

 will not suffer me to canvass written opinion 

 concerning her to any greater extent than 

 such opinion shall be confirmed as cor- 

 responding witn natural truth. Oat of all 

 that loose and flighty imagery which anato- 

 mists of the transcendental school have in- 

 dulged in, I select the first and only truth 

 which has ever been fairly established, viz. 

 that one respecting the homology between 

 cranial and vertebral structures. That this 

 homology exists between the osseous enve- 

 lope of the cerebral mass and the osseous 

 coverings of the spinal chord, is now a fixed 

 and immoveable fact in anatomical science. 

 But though the existence of this homoloiry 

 is now undeniable, still I may remark that 

 every observation which serves to prove 

 something further in respect to spinal verte- 

 bra?, which had not been known previously to 

 the recognition of this cranio-spinal resem- 

 blance, must also prove that the same thing 

 was unknown respecting cranial vertebrae. 

 Every new fact, established upon the com- 

 parison of spinal vertebrae, must be new also 

 in regard to cranial vertebrae ; and this is the 



* Oken is generally acknowledged as the signal 

 discoverer of the homology between cranial and 

 spinal segments. He believed that the cranial struc- 

 tures were repetitions of the osseous quantities pro- 

 per to the cervical vertebrae. It is said by some 

 anatomists with Meckel, that Frank first recognised 

 this analogy between the skull and the vertebras 

 (Sammlung Auserlesener Abhandlungen, Band XV. 

 S. 267.). Burdin supposed the head to be a com- 

 plicated vertebra (Conrs d'Etudes Medicates, Paris, 

 1803, vol. i. p. 16.). Keilmeyer believed the same. 

 Next Geoffrey St. Hilaire, Dumeril, and Goethe ex- 

 tended the theory, making such observations as are 

 at present considered to be purely hypothetical, and 

 little better than fanciful vagaries which almost 

 overshadow the first truth. The similitude drawn 

 by Goethe between the facial bones and the ver- 

 tebrae, is scarcely less absurd than the likeness which 

 Oken and Spix are supposed to have seen between 

 the temporal styloid process and the sacrum, or 

 between the hyoid apparatus and the pelvis. Hence, 

 it is not to be wondered at why Cuvier mocked the 

 cranial vertebral theory, when we find Spix seeking 

 for a repetition of the regions of the trunk of the 

 body in the head ; and, because he would bend na- 

 ture to his wild unstable fancy, whether she were 

 willing or otherwise, so we have him representing 

 the pelvis in the temporal bone; and likening the 

 hind limbs to the lower maxilla; the auditorv ossi- 

 cles to the pubis ; the maxillary condyle 'to the 

 femur; the coronoid process to the tibia, &c. &c. 

 See Cephalogenesis, sen Capitis ossei Struct ura. 

 For Oken's views of this subject, see Isis, 1820, 

 No. 6. p. 552. ; Esquisse d'un Systeme d'Anatomie 

 de Physiol. &c., Paris, 1821, p. 41.; also Ueber die 

 Bedeutung der Schadelknochen, Jena, 1817. 



