THE PSYCHIC DEVELOPMENT OF YOUNG ANIMALS 61 



opinion I have expressed that among animals the degree of advancement in co-ordinated 

 movements is a fairly good guide to psychic progress at early periods. 



What Remains to he Done. — I am now anxious, as all my work has been done on pure- 

 bred dogs, to study a litter of mongrels. 



It has been thought well to confine this paper to the study of the early development of 

 dogs. 



I can see the desirability of following up this paper by the account of some one dog 

 from birth to maturity, and possibly I may be able to do this. 



I purpose following this paper by another similar one on the development of other 

 animals in the earlier periods of existence, considerable material for which has already been 

 accumulated, so that I hope in time to get the facts in such form that broad and sound con- 

 clusions as to development of young animals may be drawn. 



As the dog, after the monkeys and apes, more closely resembles man })yschically than 

 any t)ther animal, it seems to me that it would be very profitable to attempt a comparison of 

 the development of the young dog and the infant. But this task must also be deferred. 



For various reasons I have not referred in detail to the fragmentary work of others, 

 chiefly because the original papers are not in most cases accessible to me now, and because 

 prolonged discussions and comparisons with their results would add to the length of an 

 already long paper. I present my observations with such conclusions as I have tried to 

 draw cautiously and without prejudice, believing that whatever their defects they constitute 

 the most complete account of the subject published to date. 



Some Conclusions. — The dog is born blind and deaf He possibly smells and tastes 

 feebly, but this is difiicult of demonstration ; but in any case he smells, tastes, has tactile 

 and muscular sensations, the temperature sense and can experience pain before he can either 

 see or hear. 



The eyes are open before the ears, but seeing objects does not correspond in time with 

 the opening of the eyelids, which is gradual, the result of.j)rocesses of growth and absorp- 

 tion. Hearing follows sooner on complete opening of the ears than seeing on opening of 

 the eyes. 



There is progressive improvement in both seeing and hearing. 



Both begin about the 17th day and are in a high state of perfection about the 30th day ; 

 hearing being upon the whole rather more rapid in development. 



Smell and taste are demonstrable on the 13th day, and are well developed about the 

 30th day. 



Newly born dogs are very much affected unfavourably by a temperature below a certain 

 moderate point (50^ or 60° F.). Are capable from the first of such movements as enable 

 them to avail themselves of the heat from the mother's body. 



They give evidence of feeling hunger and are capable of making certain slow move- 

 ments at birth. 



They find the teats chiefly if not wholly by touch ; and continue sucking in consequeuce 

 of the satisfactioa of the appetite for food. 



Up to about the 20th day, puppies are very readily fatigued, and incapable of attention 

 to anything for more than a very few seconds at one time. 



They early show an appreciation of any decided change in the environment, indicating 



