THE PSYCHIC DEVELOPMENT OF YOUNG ANIMALS 213 



to enlarge the opening in fact, he behaves in this very 

 much like a mature dog. 



56th day. When he is out of his compartment (the 

 door open) and he is told to go in, and one stamps with 

 the foot, he retreats to his box, but soon wants to come 

 out again. 



63rd day. He now mingles with all the dogs of the 

 kennel, large and small, seems to enjoy the life, and 

 manages to adapt admirably to his entire environment. 



69^ day. Prior to defsecation moves about, smells, 

 turns round and round, etc., just like an old dog. 



Shows sexual feeling, if one may judge by his actions 

 towards a mature bitch. 



87th day. Since the last record, his progress in 

 adaptation and in general development has been steady. 

 As the chief stages in development had been now over- 

 taken, he was removed to my laboratory for experiment 

 on the brain. 



Remarks on the Diary. 



Observations on the temperature sense, tactile sensi- 

 bility, and the sense of pain were not made as early as 

 desirable in the pure-bred puppies, but this omission 

 was made good in the present case, as the diary shows, 

 and there can be no doubt that these senses all exist 

 from the moment of birth. The evidence that true 

 smell, as distinguished from the mere sense of irritation 

 of the nose by pungent vapours, is less conclusive, 

 while that for taste is more doubtful still. 



The increasing development of tactile sensibility, and 

 especially the readiness of the nervous system to respond 

 to stimuli acting on the nasal mucous membrane, is well 

 illustrated by the observations recorded at different 

 times in the early life period of the puppies. 



Both smell and taste are very feebly developed before 

 the eyes are open, but about the 10th day there was 



