Dr. Foville on the Anatomy of the Brain. 31 



skull. So far from that, observation proves that when the 

 convolutions are greatly developed, the skull, though retain- 

 ing the form that we have assigned to it, swells out in the 

 intervening regions between the eminences corresponding to 

 the extremities of the ventricles, so as almost to obliterate 

 them ; or if they still remain very prominent, they acquire a 

 very great diameter. In this case, the head, modified by the 

 development of the convolutions, acquires the cerebral form, 

 par excellence. 



On the contrary, when the convolutions are but very little 

 developed, the prominences, and the regions separating them, 

 are all exceedingly well marked, whilst, at the same time the 

 projections corresponding to the ventricular extremities have 

 a very small diameter. The head then assumes, if I may be 

 allowed to use such a term, the peculiarly ventricular form. 



The relations just now pointed out between the projecting 

 points of the skull and the corresponding regions of the ven- 

 tricles, appear still further confirmed by observing what takes 

 place in chronic hydrocephalus. One of the first symptoms 

 of this dropsy of the ventricles is the increased salience of 

 these cranial tumours. But I shall not pursue the details of 

 the relations between the skull and the brain any further at 

 present. I consider them useful in reference to what is called 

 surgical anatomy, and also for all those cases which call for 

 an exact knowledge of the relations between the skull and the 

 brain. The subject has been pursued in a work of some ex- 

 tent, which I intend before long to lay before the public. 



To sum up, I consider that the fibrous parts of the brain 

 are conductors; some from without to within, others from 

 within to without. I believe that these conducting parts may 

 be distinguished into afferentes and efFerentes, and that the 

 distinct course of both the one and the other may be demon- 

 strated. The first are inserted especially into the circum- 

 ference of the gray substance, and the second into its internal 

 surface. 



The gray substance of the convolutions intermediate be- 

 tween the two preceding orders of fibrous parts, seems to 

 me to be the material substratum, through the instrumentality 

 of which the will directs the movements of the body. 



The prominences constantly seen coupled in pairs on the 

 arch of the skull appear to me to be produced by the pro- 

 jection of the corresponding regions of the ventricles. The 

 median eminences, not aniversally present, appear to be pro- 

 duced by a thickening of the bones. 



The median zone of the cranial arch is naturally divided 

 into four sections ; one, anterior, corresponding to the fore 

 part of the corpus callosum, and to the convolutions de- 



