286 ON THE STRUCTURE OF THE VERTEBRATE SKULL. 



cesses ; the two frontals form the spinous process, together with 

 its lateral parts. 



" The sphenoid is separated into two vertebrae, not merely in 

 the human foetus and in Ruminants, but also in the Apes, in 

 Bradyjms tridadylus, Dasypus novemcinctus, Dog, Wolf, Bear, 

 Otter, Rodents, and probably in all Mammals, if examined in a 

 sufficiently young state. The law is therefore universal. 



" The inter- vertebral foramina are very well marked between 

 these vertebrae. A deviation seems to exist, on account of the 

 foramina which lie in front of the first cephalic vertebra, namely, 

 the foramen caroticum and lacerum, concerning which I must 

 leave it undecided, whether they are originally two, or only one 

 which has become separated. On this point, evidence enough is 

 to be found among animals. The organ of hearing has here 

 interposed itself. On the other hand, it is characteristic of the 

 cephalic vertebrae that their sides are perforated by nerves, — 

 by the optic nerve, the jaw nerves, and the hypoglossus, if we 

 reckon the auditory and facial nerves as inter-vertebral nerves : 

 a circumstance which demands further inquiry. 



" So much of the cephalic vertebral column. I might have 

 been able to treat more fully and thoroughly of it, and to have 

 indicated the nerves, veins, and muscles, which in the head cor- 

 respond to those of the trunk, and the like for the bones ; but 

 in a programme one must be content with merely putting forth 



one's view of a question. 



"II. 



" If the cerebral capsule is the repetition of the spinal 

 column, only more expanded and organized (I speak as an 

 anatomist), the head must repeat the outgrowths of the spinal 

 column, the thorax, the pelvis, and the limbs ; and, indeed, 

 thereby must it attain completeness. 



" By this union of the representatives of all the bones of the 

 trunk arises the wonderful, but yet analvsable, mixture and 

 intercurrence of formations which appear as the facial bones. 

 The spinal column becomes the brain-case ; the walls of the 

 trunk, with the extremities, become the face." 



In developing this idea, Oken arrives at the conclusion that 

 the nasal cavity is the thorax of the head, and the oral cavity 



