Observations on Young Mammals. 1 1 1 



shortly after, to warmth and cold, and show a tendency 

 to seek the warmth of the mother's body, for example. 

 Sensitiveness to touch seems also quite early developed. 

 When the mouth or nose of a kitten, on the second day, 

 was touched, and especially when the inner surface of the 

 nostrils was irritated, withdrawal of the head followed. 

 With young rabbits, on their first day, the slightest touch, 

 or even a light puff of air from the mouth, causes much 

 disturbance; they move in an irregular, ill co-ordinated 

 way, but evidently are greatly affected. A fly crawling 

 across the face caused jerky movements of the head 

 as a whole, and of the ears. When solutions of Epsom 

 salts and of common salt were placed in the mouth of 

 a rabbit not twenty-four hours old, to test its power of 

 taste, there was some movement of the paws to wipe it 

 away. On the seventh day it used the paws fairly well 

 to get rid of any irritant, such as a feather, put against 

 the mouth. The period that elapses between stimulus 

 and response varies. In the dog and cat, for example, 

 there is a much longer " latent period," in the case of 

 the reflex started by a pinch, than is shown by the rabbit. 

 On the sixteenth day a kitten was seen to use the hind 

 leg to scratch the ear or head ; and such a reflex is seen 

 in the dog at about the same time (seventeenth day). 

 In both these animals, as before noted, the co-ordinated 

 movements of the hind limbs develop somewhat slowly. 

 A Himalayan rabbit, on the other hand, used its hind 

 leg to scratch itself as early as the second day. There 

 can be little doubt that such reflexes, whereby local irri- 

 tations are connected with limb-movements effective for 

 their removal, are congenital in their nature, and form 

 the basis of further and more accurate localization of the 

 point of irritation, and of further adaptation of the move- 

 ments necessary for its removal. 



