THE PSYCHIC DEVELOPMENT OF YOUNG 

 ANIMALS AND ITS PHYSICAL (SO- 

 MATIC) CORRELATION, WITH SPECIAL 

 EEFERENCE TO THE BRAIN. 



IT seemed to me important that psychic and somatic 

 development should be traced contemporaneously, so 

 closely are they related, and in the preceding papers 

 an attempt was made to realise, to some extent, this 

 ideal, but as my researches on the brain were not 

 completed till after the publication of these investiga- 

 tions, I thought it better not to attempt to utilise them 

 at the time. The investigation bearing on the functional 

 development of the cerebral cortex, with special regard 

 to the motor centres, extends to all the groups of 

 animals falling under my studies in psychic develop- 

 ment, and is presented 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. Naturally, 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 regard to a more com- 

 plete correlation of the somatic with the psychic. 



No attempt will be made in this paper to discuss 

 somatic correlation in general, as that subject has been 

 treated in the previous papers. 



It would be quite correct to speak of the relations as 

 anatomical and physiological correlation, but as move- 

 ments are so bound up with the psychic developments of 



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