93 



LECTURE IV. 



structure of the Brain. — Elementary Constituents of Brain-substance. — Ce- 

 rebelliim. — The primitive Brain. — The Cerebrum the seat of intellectual 

 activity. — Localisation of individual functions. — Application to Phreno- 

 logy. — The Cerebral Lobes. — The Convolutions : their relation to the In- 

 tellect and the Size of the Body. — The development of the Convolutions, 

 and their arrangement according to Gratiolet and Wagner. — Huschke's 

 Opinions. — Comparative Investigation of various Cerebral Forms. — The 

 Cerebral Cavities. — Dispute about them, especially in England. 



Gentlemen, — Whatever opinion we may entertain regarding 

 the intellectual functions, whether they be regarded as the 

 manifestations of an independent soul by the intermediation of 

 the nervous system, or as the functions of the nervous system 

 itself and its parts, we are always reduced to the necessity of 

 considering the brain as the organ from which the intellectual 

 functions proceed. Every disturbance in the cerebral struc- 

 ture, by whatever agency it may be produced, is immediately 

 reflected in the intellectual functions ; it may even be pre- 

 dicted, in many instances, that laceration will be followed by 

 certain effects, and even every change in the cerebral circula- 

 tion immediately influences cerebral activity. If this be true, 

 and no one can doubt it, for stupor and epileptic fits may be 

 produced experimentally in any animal, we can easily imagine 

 that the structure of the brain and its component parts stands 

 in the most intimate relation to the development of the in- 

 tellectual function, and that this mode of relation may be, 

 though at present only approximatively, ascertained. The 

 structure of the brain is exceedingly complicated ; there is no 

 organ in the human body which, consisting of comparatively 

 so few elementary constituents, possesses so great a variety of 

 parts which, by their shape, internal structure, and position. 



