THE PSYCHIC DEVELOPMENT OF YOUNG ANIMALS 



and the body must be studied together will, I am satis- 

 fied, become more and more evident as investigations on 

 the one, independently of the other, prove disappointing. 

 This applies more particularly, no doubt, to the mind, but 

 not wholly. While to a practised observer very many 

 shades of change in physical developments may be 

 observed, there is no good method of measuring most of 

 them, and it is more than difficult to express much of 

 what is observed in a way to make it appreciable by 

 the mind of the reader. 



Until our knowledge of the relations between the 

 mind and the body between the history of the body 

 and that of the mind between ontogeny and psychogeny 

 (psychogenesis) is made very much more complete, it 

 would appear that it is desirable that a contemporaneous 

 account be kept of every change of whatever kind 

 observed, both physical and psychic. 



We dare scarcely say that matters so apparently 

 trivial as the change in colour of the iris, or as the 

 pigmentation of the nose, for example, are in no relation 

 whatever with psychic development. 



Has the eruption of the teeth in the puppy no 

 relation to psychic growth and development? In 

 itself the direct causal relation from increasing experi- 

 ence thus afforded by their use is not all, and there is 

 doubtless in this more than we are in a position to 

 define as yet. As soon as the teeth appear, and the 

 jaws are more used, as is now the tendency, the puppy 

 advances in consequence of this very use of teeth and 

 jaws, but this is probably not the whole story. 



From the chief diary, and the comments on it, the 

 reader will be able to cull many instances of psychic 

 and physical correlations. Between the physical 

 changes in the eye and ear especially, and the psychic 

 results, the closest relation is evident, and this should 

 suggest that similar close connection exists elsewhere. 



