[MILLS] PSYCHIC DEVELOPMENT OF YOUNG ANIMALS 217 
49th day.—The puppy is playing in the yard. Scratches at the 
snow like an old dog. After defiecation he draws himself along in the 
snow. 
He pulls at the withered branch of a vine growing against a fence. 
He ascends a snowbank in the yard wagging his tail. 
He seems very much at home with the older dogs and adapts well to 
his surroundings. 
52nd day.—The last remark applies with much greater force now. 
lle is very free in all his movements. Carries his tail up and wags 
it vigorously. 
Considerable change is observable in the shape of his muzzle within a 
few daye. 
On being given a bone he does not commence on it at once but carries 
it to his bed instead of gnawing it on the sawdust that covers the floor 
of his pen. 
58rd day.—To-day the puppy is trying hard to get out of his com- 
partment, pushing his head through between the iron-wire door and the 
sill and using his paws 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. 
69th day.—Prior to defiecation 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. 
S?th day.—Since the last record his progress in adaptation and in 
general development has been steady. As the chief stages in develop- 
ment had been now overtaken he was removed to my laboratory for 
experiment on the brain. 
REMARKS ON THE DIARY. 
Observations on the temperature sense, tactile sensibility, and the 
sense of pain were not made as early as desirable in the pure-bred pup- 
pies, 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 conclu- 
sive, 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 
