Sec. IV., 1896. [ 19 ] Trans. R. S. C. 



IJ. — The Psychic Development of Young Animals and its Physical 

 (Somatic) Correlation ivith Special Reference to the Brain. 



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

 Professor of Physiology in McGill University, Montreal. 



(Read May 20, 1896.) 



It seemed to me important that psychic and somatic development 

 should be traced contemporaneously, so closely are they related, and in the 

 six papers printed in these Transactions for 1894 and 1895, an attempt 

 was made to realize, to some extent, this ideal, but as my researches on 

 the brain were not completed till alter the publication of these investiga- 

 tions I thought it better not to attempt to utilize them at the time. The 

 investigation bearing on the functional development of the cerebral cortex, 

 with special i^3gard to the motor centres, extends to all the groups of 

 animals falling under my studies in psychic development, and is pre- 

 sented in the present volume of the Transactions, so that it is now 

 possible to deal with the most important part of the somatic correlation^ 

 viz., with the brain. ]Sraturally I shall draw chiefly from the latter paper 

 and from those on psychic development for the facts, etc., on which 

 reliance will be placed in attempting further progress in regai^d to a 

 more complete correlation of the somatic with the psychic. 



îfo attempt will be made in this paper to discuss somatic correlation 

 in general as that subject has been treated in the papers previously pub- 

 lished in these Transactions. 



It would be quite correct to sj)eak of the relations as anatomical 

 and physiological correlation, but as movements are so bound up with 

 the psychic developments of animals I think it will be more instructive 

 to consider the subject from this jjoint of view, and in doing so the 

 psychic will be first taken into account. 



I.— The Dog. 



As soon as a puppy is born, it is capable of cries, crawling and suck- 

 ing, and if we except those concerned with the vital or vegetative func- 

 tions, these about cover all its possible movements. Up to the period 

 when the eyes open, there are no new movements. Every one of these 

 can be produced experimentally as reflexes, and the question is, are they 

 naturally of this character. They improve from day to day, but that is a 

 feature of all reflexes, even the best organized (as swallowing) though it 

 has hardly been adequately recognized. 



