THE PROGRESS OF DEGRADATION. 175 



(lerfal one. We can see but imperfectly in those twilight 

 depths to which all such subjects necessarily belong ; and yet 

 at times enough does appear to show us what a very super- 

 ficial thing infidelity may be. The general advance in crea- 

 tion has been incalculably great. The lower divisions of the 

 vertebrata preceded the higher ; — the fish preceded the rep- 

 tile, the reptile preceded the bird, the bird preceded the mara- 

 miferous quadruped, and the mam miferous quadruped preceded 

 man. And yet, is there one of these great divisions in which, 

 in at least some prominent feature, the present, through this 

 mysterious element of degradation, is not inferior to the past ? 



other, to protect the centres of the nervous system, by forming a more 

 or less solid case completely around them. The bodies of the vertebrae 

 are particularly destined to the first of these oflices ; the neurapophyses 

 to the second. What can be more natural than to admit, from the con- 

 sideration of this, that in the head the bodies of the vertebrae diminish in 

 proportion as the moving function becomes lost, while the neurapophyses 

 are considerably developed for protecting the brain, the volume of which 

 is very considerable, when compared with that of the spinal marrow ? 

 Have we not an example of this fact in the vertebrae of the tail, where 

 the neurapophyses become completely obliterated, and a simple cylindri- 

 cal body alone remains ? Now, may it not be the case that, in the head, 

 the bodies of the vertebrae have disappeared ; and that, in consequence, 

 there is a prolongation of the cord only as far as the moving functions 

 of the vertebrae extend ? There is some truth in this argument, and it 

 would be difficult to refute it a priori. But it loses all its force the mo- 

 ment that we enter upon a detailed examination of the bones of the head. 

 Thus, what would we call, according to this hypothesis, the principal 

 sphenoid, the great wings of the sphenoid, and the ethmoid, which form 

 the floor of the cerebral cavity ? It may be said they are apophyses. 

 But the apophyses protect the nervous centres only on the side and above. 

 Tt may be said that they are the bodies of the vertebrae. But they are 

 formed without the concurrence of the dorsal cord ; they cannot, there- 

 fore, be the bodies of the vertebrae. It must therefore be allowed, that 

 these bones at least do not enter into the vertebral type ; that they are 

 in some measure peculiar. And if this be the case with them, why may not 

 the other protective plates be equally independent of the vertebral type ; 

 the more so because the relations of the frontals and parietals vary so 

 much, that it would be almost impossible to assign to them a constant 

 place r 



