244 report — 1846. 



represented by divisions of the compound lower jaw in the crocodile and 

 embryo bird (see Table, No. III.). The pterygoids (24), the essential di- 

 stinction of which from the sphenoid Oken clearly recognises, are his ' clavi- 

 cular capitis.' Oken hints at, without accepting, the (serial) homology of 

 the hyoid arch with the pelvis ; but he regards the stylohyal (3s) as the 

 4 sacrum capitis' (ib. p. 16). 



The year after the publication of Oken's famous ' Introductory Lecture,' 

 Prof. Dumeril, apparently unacquainted with its existence, communicated 

 to the French Institute a memoir entitled ' Considerations generates sur 

 l'analogie qui existe entre tous les os et les muscles du tronc dans les ani- 

 maux,' the second paragraph of which is headed " De la tete considered 

 comme une vertebre, de ses muscles et de ses mouvements." In this para- 

 graph, repeating the homological correspondences, demonstrated by Oken, 

 between the basioccipital as a vertebral centrum, the condyles as ' oblique 

 processes,' and the occipital protuberance as a spinous process, he adds, that 

 the mastoid processes are entirely conformable to transverse processes. And 

 M. Dumeril has, I believe, here the merit of having first enunciated the 

 general homology of the mastoids, although he does not aim at showing to 

 •which vertebral segment of the skull they properly belong. Nor, indeed, 

 with the exception of an observation that " very often the body of the sphe- 

 noid, like the ' apophyse basilaire' of the occiput, resembles the body of a 

 vertebra," does he push the transcendental comparisons further. GeofFroy 

 St Hilaire tells us*, that even the moderate and very obvious illustrations 

 of the general homologies of the cranial bones, which M. Dumeril deduced 

 from the anatomy of the occiput, excited an unfavourable sensation in the 

 bosom of the ' Academie;' and that the phrase ' vertebre pensante,' which a 

 facetious member proposed as an equivalent for the word ' skull,' and which 

 circulated, not without some risibility, along the benches of the learned 

 during the reading of the memoir, reaching the ears of the ingenious author, 

 the dread of ridicule checked his further progress in the path to the higher 

 generalizations of his science, and even induced him to modify considerably 

 many of the (doubtless happy) original expressions and statements in the 

 printed report, so as to adapt it more to the conventional anatomical ideas 

 of his colleagues. 



As the truth of Oken's generalization began to be appreciated, it was remem- 

 bered, as is usually the case, that something like it had occurred before to 

 others. Autenrieth and Jean-Pierre Frank had alluded, in a general way, to 

 the analogy between the skull and the vertebral column : Ulrich, reproducing, 

 formally, Oken's more matured opinions on the cranial vertebrae, says, 

 " Kielmeyerum praeceptorem pie venerandum quamvis vertebram tanquam 

 caput integrum considerari posse in kcholis anatomicis docentem audivi." 

 And the essential idea was doubtless present to Kielmeyer's mind, though 

 he reversed M. Dumeril's proposition, and, instead of calling the skull a ver- 

 tebra, he said each vertebra might be called a skull. But these anticipations 

 detract nothing from the merit of the first definite proposition of the theory. 

 It would rather be an argument against its truth, if some approximative idea 

 had not suggested itself to other observers of nature, who only lost the merit 

 of developing it, from not appreciating its full importance. He, however, 

 becomes the true discoverer who establishes the truth : and the sigu of the 

 proof is the general acceptance. Whoever, therefore, resumes the investiga- 

 tion of a neglected or repudiated doctrine, elicits its true demonstrations, 

 and discovers and explains the nature of the errors that have led to its tacit 



* Annates des Sciences Naturelles, t. iii. 1824, p. 177. 



