THE PROGRESS OF DEGRADATION. 173 



long cycles of the primal one. It indicates, not the starting 

 point from which the race of creation began, but the stage of 

 retrogradation beyond it at which the pilgrims who set out 

 in a direction opposite to that of the goal first arrived.* 



* I would, however, respectfully suggest, that that theory of cerebral 

 vertebrae on which, in this question, the comparative anatomists proceed 

 as their principle, and which finds as little support in the geologic record 

 from the actual history of the fore limbs as from the actual history of the 

 bones of the cranium, may be more ingenious than sound. It is a shrewd 

 circumstance, that the rocks refuse to testify in its favour. Agassiz, I 

 find, decides against it on other than geological grounds ; and his con- 

 clusion is certainly rendered not the less worthy of careful consideration 

 by the fact that, yielding to the force of evidence, his views on the sub- 

 ject have undergone a thorough change. He first held, and then rejected 

 it. "I have shared," he says, " with a multitude of other naturalists, 

 the opinion which regards the cranium as composed of vertebrae ; and I 

 am consequently in some degree caled upon to point out the motives 

 which have induced me to reject it." 



** M. Oken," he continues, " was the first to assign this signification to 

 the bones of the cranium. The new doctrine he expounded was received 

 in Germany with great enthusiasm by the school of the philosophers of 

 nature. The author conceived the cranium to consist of three [four] verte- 

 brae, and the basal occipital, the sphenoid, and the ethmoid, were regarded 

 as the central parts of these cranial vertebrae. On these alleged bodies of 

 vertebrae, the arches enveloping the central parts of the nervous system 

 were raised, while on the opposite side were attached the inferior pieces, 

 which went to form the vegetative arch destined to embrace the intes- 

 tinal canal and the large vessels. It would be too tedious to enumerate 

 in this place the changes which each author introduced, in order to modify 

 this matter so as to make it suit his own views. Some went the length 

 of affirming that the vertebrae of the head were as complete as those of 

 the trunk ; and, by means of various dismemberments, separations, and 

 combinations, all the forms of the cranium were referred to the vertebrae, 

 by admitting that the number of pieces was invariably fixed in every 

 head, and that all the vertebrata, whatever might be their organization 

 in other respects, had in their heads the same number of points of ossifi- 

 cation. At a later period, what was erroneous in this manner of regard- 

 ing the subject was detected ; but the idea of the vertebral composition 

 of the head was still retained. It was admitted as a general law, that 

 the cranium was composed of three primitive vertebrae, as the embryo is 

 of three blastodermic leaflets ; but that these vertebrae, like the leaflets, 

 existed only ideally, and that their presence, although easily demonstrated 



