Sec. IV., 1896. [ 2S ] Trans. E. S. C. 



III. — Cortical Cerebral Localization, icith Special Reference to Rodents 



and Birds. 



By Wesley Mills, M.A.. M.D., F.E.S.C, 



Professor of Physiology in McGill University, Montreal. 

 (Read May 20, 1896.) 



During the course of an investigation' on the "Functional Develop- 

 ment of the Cerebral Cortex" in the Cat, the Dog, the Babbit, the Cav}- 

 (Guinea-pig), etc., the question of the completeness and accuracy of the 

 published researches on localization was often forced upon my notice, 

 and never having found a cortical cerebral centre for the hind -limb in 

 young rabbits. I was led to investigate this subject in the mature animal, 

 and being unable to discover such a centre, it occurred to me that the 

 whole subject of cerebral cortical localization in animals below the carni- 

 vora, at all events, was worthy of further study. Accordingly I have 

 subjected the rabbit, the cavy, the rat, the mouse and the bird to experi- 

 ments in order to determine the correctness and adequacy of existing 

 views on localization. 



I turned nattirally to the classical work of Ferrier," which gives this 

 writer's views in a clear and concise form. This investigator defines a 

 centre for movements of the hind-limb in the rabbit near the middle line 

 and immediately behind that for the fore-limb. While my own work 

 was in progress, Gustav Mann published a research on cortical localiza- 

 tion,* in which he attempted to deal with the subject in a manner more 

 exact and complete than had hitherto been done. He also gives an ac- 

 count of the work previously accomplished by Ferrier and others. Apart 

 from Ferrier's distinct statement, there does not seem to be ver}^ clear 

 evidence in the literature of the location of a well-detined centre for the 

 hind-limb. 



Mann himself locates a centre for the hind-limb posterior to that for 

 the neck and arm and near the middle line. 



Speaking of his methods, Dr. Mann says : " As regards the eiyeri- 

 mental i^art of my research, the hedgehogs and cats were kept ana?s- 

 thetized during the whole period of the experiment, while the rabbits 

 were anaesthetized to render the preliminary operation painless, and then 

 allowed to regain consciousness." * 



1 Published in these Transactions for the current year. 



2 " The Functions of the Brain," 2nd éd., London, 1886. 



■* "On the Homoplasty of the Brain of Rodents, Insectivores and Carnivores," 

 Journ. of Anat. and Phys., October, 1895. 

 ^ Loc. cit., p. 225. 



