ON THE VERTEBRATE SKELETON. 309 
The course of coalescence reduces the epencephalic arch (fig. 25, N 1) to 
one bone, the scapular arch to one bone (the arch is apparently completed 
by the connexion of an element (s2') not appertaining to the skull). The 
centrums 5, (9) and neurapophyses (6, 10) of the parietal and frontal vertebra 
coalesce together and with the diverging appendages (21) 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 asingle bone. ‘The halves of the 
nasal spine (13) rarely coalescing are counted as two bones. The mastoid (s) 
coalescing with the petrosal (16) and this with the tympanic(2s), squamosal (27) 
and stylohyal (ss), 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 
(14) coalesce with each other and with a considerable part of another ossified 
sense-capsule (1s), 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 (46). The scapula includes both the pleurapophysis (51) 
and the hemapophysis (52) of the occipito-hemal arch. The signification of 
the separate points of ossification of the human fcetal 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 vertebre 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 vertébre ou un composé de trois ou quatre vertébres?” appended to 
the posthumous edition of the ‘Lecons d’Anatomie Comparée*,’ 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 vertebree ; 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”}. “‘ 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, 
bears only upon the @ priori cranio-vertebral theory of Geoffroy, and does not concern us 
here. 
+ “L’analogie de ces trois piéces, Je basilaire et les deux condyloidiens, avec les trois 
piéces de l’atlas, son corps et les deux moitiéy de sa partie annulaire est trés sensible. Le 
basilaire et le corps de l’atlas servent également 4 supporter Ja moélle épiniére ; les condy- 
