ON THE VERTEBRATE SKELETON. 309 



The course of coalescence reduces the epencephalic arch (fig. 25, N i) to 

 one bone, the scapular arch to one bone (the arch is apparently completed 

 by the connexion of an element (52') not appertaining to the skull). The 

 centrums 5, (9) and neurapophyses (0, 10) of the parietal and frontal vertebras 

 coalesce together and with the diverging appendages (24) of the maxillary arch 

 to form one bone, the ' sphenoid ' of anthropotomy, and this ultimately coa- 

 lesces with the epencephalic arch and constitutes the' os spheno-occipitale ' of 

 Soemmerring. The expanded halves of the parietal spine (7) remaining 

 usually distinct are reckoned as two bones. The expanded halves of the frontal 

 spine (11) usually coalescing together form a single bone. The halves of the 

 nasal spine (13) rarely coalescing are counted as two bones. The mastoid (s) 

 coalescing with the petrosal(ie) and thiswith the tympanic(2s), squamosal (27) 

 and stylohyal (3s), the whole is reckoned a single bone, which thus combines 

 a parapophysis and pleurapophysis of one vertebra with a pleurapophysis of 

 another and a diverging appendage of a third vertebra, and all these parts of 

 the endo-skeleton become confluent with a sense-capsule belonging to the 

 splanchno-skeleton : such is the heterogeneous compound character of the 

 ' temporal bone ' of anthropotomy. The neurapophyses of the nasal vertebra 

 (u) coalesce with each other and with a considerable part of another ossified 

 sense-capsule (is), to form the single bone called ' ethmoid.' The maxillary 

 bone includes the superior maxillary (21) and premaxillary (22) of the lower 

 animals. The hyoid bone includes the basihyal (41), with the ceratohyals (40) 

 and the thyrohyals (40). The scapula includes both the pleurapophysis (51) 

 and the hasmapophysis (52) of the occipito-hsemal arch. The signification of 

 the separate points of ossification of the human foetal skull is made plain by 

 the foregoing applications of the ascertained general homologies of the bones 

 of that part of the skeleton. 



Objections to the Cranial vertebrce considered. — The latest and most formal 

 objection to the fundamental idea on which the general homologies of the 

 bones of the head have been worked out in the present Report, is also 

 the most formidable in respect of the great and deserved eminence of the 

 objector. In a manuscript left by Baron Cuvier, entitled, " Le crane est-il 

 une vertebre ou un compose de trois ou quatre vertebres ?" appended to 

 the posthumous edition of the { Lec.ons d'Anatomie Comparee*,' he admits 

 that "the analogy of the basilar and two condyloid parts of the occiput with 

 the body and two halves of the annular part of the atlas is very appreciable. 

 The basioccipital and the body of the atlas serve equally to support the 

 myelon ; the exoccipitals and the two halves of the ring of the atlas to cover it. 

 The condyles are represented by the articular processes by which the atlas is 

 joined to the dentata. The condyloid foramen, which gives passage to the 

 nerve of the ninth pair, has some relation with the hole in the atlas which 

 gives passage to the first cervical nerve and to the first bend of the vertebral 

 artery. Some have also found a certain relation between the mastoid process, 

 which in most animals appertains to the occipital bone, and the transverse 

 process of the atlas and the other vertebra? ; upon which it must be remarked 

 that these relations are less in man, in some respects, than in the quadrupeds, 

 since the atlas has commonly only a notch for the passage of the artery, and 

 the mastoid belongs in man entirely to the petrosal "f. " We may even com- 



* Tome ii. p. 710. (1837) par MM. F. G. Cuvier and Laurillard, who hold the arguments 

 of their author to be conclusive. The criticism in the ' Histoire des Poissons,' t. i. p. 230, 

 hears only upon the a priori cranio-vertebral theory of Geoffroy, and does not concern us 

 here. 



t " L'analogie de ces trois pieces, le hasilaire et les deux condylo'idiens, avec les trois 

 pieces de l'atlas, son corps et les deux moities de sa partie annulaire est tres sensible. Le 

 basilaire et le corps de l'atlas servent egalement a supporter la moelle epiniere ; les condy- 



