Researches on the Anatomy of the Brain. 285 



of a membrane over the thalami optici in the direction from 

 within outwards, and which, afterwards uniting into a cord, 

 pass round the crura cerebri, and having decussated, consti- 

 tute the optic nerves. 



We thought it required of us to give this exposition of the 

 principal methods which have of late been proposed to make 

 known the structure of the brain. Having done so, we will 

 now proceed to analyse the memoir of Dr. Foville. [Believing 

 that the Doctor's views will be best understood from his own 

 explanation of them, 1 here insert the translation of his me- 

 moir ; and to avoid needless repetition, I suppress that part of 

 the report which merely consists of the epitome of the paper. 



Researches on the Anatomy of the Brain, presented to the Royal 

 Acadeviy of Sciences of Paris, by Dr. Foville, Bx-internal 

 Eleve of the Civil Hospitals of Paris ; Principal Physician 

 of the Lunatic Asylum for the Department of the Lower 

 Seine, Sfc. 



Gentlemen, 



During six years in which I was connected with the medical 

 service of the hospitals of Paris, I had the privilege of being 

 placed in immediate relation with those whose labours on the 

 subject of the diseases of the brain have mainly contributed to 

 the advancement of this branch of science. I endeavoured to 

 profit by the advantages of my position, by imbibing their ob- 

 servations and making myself master of their doctrines. 



For this object it was most essential to have I'ecourse to 

 that foundation, without which all medical theories vacillate 

 on the brink of annihilation, — on anatomy, which has ever been 

 most in arrear in that which relates to the structure of the 

 brain. 



It is true that very important observations had been made 

 respecting the general development of the nervous system, and 

 on its gradual complication in the scale of animals; and that 

 anatomists are pretty well agreed as to its general composition. 

 We are nevertheless ignorant of the structure of its principal 

 parts ; and the most widely received opinions with respect to 

 them, are perhaps nothing more than ingenious hypotheses, 

 whicli accurate observation may overthrow. 



I saw that it was necessary that I should examine for my- 

 self. The first object of my researches was to verify accredited 

 theories. Their first result was to inspire me with doubt re- 

 specting the validity of those theories. In the course of these 

 researches I was struck witli certain constant dispositions in 

 tlie cerLbral organization, which appeared to me to have been 



hitherto 



