Section IV., 1894. [ 31 ] Trans. Eoy. Soc. Canada. 



III. — 77/'' P'^i/iJiii- Drvclopiiuiit of YoiiiKj Aniindls (uid il.s Phi/^iraJ Correlafioii. 



By Wesley Mills, M.A., M.D., F.R.S.C., Professor of Physiology in McGill 



Univei'sity, Montreal. 



(Read May 2gth, 1894.) 



THE DOG. 



Introduction. 



For mind and body alike the past determines the present in no small degree ; hence it 

 follows that the more perfectly the history of each step in the development of mind is traced 

 the better will the final product, the mature or relatively fully developed mind lie understood. 

 Anatomical researches were long conducted on the bodies of animals before the light thrown 

 on structure by embryology cleared up the obscurities which of necessity hung about 

 parts, the origin and early development of which were unknown. 



Comi)arative anatomy had already done something to give increased significance to 

 anatomy as a whole ; but it was only by tracing the animal body liack to its primitive germ 

 cells, following these cells in their development into tissues and organs by the naked eye 

 and with the microscope, comparing these changes in one animal with corresponding ones in 

 another, and indeed in plants, and interpreting them all in the light of evolution that the 

 present status of biology has been reached. 



Psychology is as yet in no such position ; but it must be equally clear to those who, 

 guided by facts alone, untrammelled by tradition and dogma of every kind, compare the 

 psychic status of the young with that of the mature animal that psychogenesis is a fact ; 

 that the mind does unfold, evolve, develop equally with the body. And as with the body 

 so with the mind, each stage in this development can only be understood in the light of all 

 the previous stages. 



This truth is apparently as yet only dimly comprehended, for till recently studies on 

 psychic history, development or psychogenesis have been all but unknown ; and as yet, even in 

 the case of man, are very few and confessedly imperfect. 



But just as we have an ontogeny and phylogeny ; just as the anatomy, physiology and 

 pathology of man are clearer from comparative studies on creatures lower in the scale, so 

 must it be in regard to man's psychology. 



It follows then that all researches in comparative psychology must be as welcome for 

 the general science of mind and the special study of human psychology as those in compara- 

 tive anatomy are to anatomy in general or the anatomy of man in particular. 



