1 1 6 Habit and Instinct. 



have died if assistance had not been given ; and she had 

 seen many instances where the teat had at length to be 

 placed in the mouth of the young pig to prevent starvation. 



" So far as I have been able to observe, the direct 

 action is most ready where the difference between the 

 temperature of the mother and that of the atmosphere 

 is greatest. Young pigs, pups, and kittens are impelled 

 towards the mother by the irregular action excited by the 

 difference of temperature much more decidedly when it 

 is great." 



We are considering, it must be remembered, the very 

 beginnings of this activity which is of such essential im- 

 portance to the young mammal. There can be no question 

 that experience plays its part in the further development of 

 the act ; and that here, as elsewhere, practice makes 

 perfect. Whether the gentle rhythmic pressure of the 

 fore paws on the mammary glands is partly instinctive, 

 it is difficult to say. No doubt experience renders the 

 act more effectual. Darwin believed that a habit of such 

 rhythmic pressure is engendered. We may often see a 

 kitten or older cat gently pounding at a cushion as she 

 lies dozing and purring. 



To revert to the initial establishment of the behaviour 

 characteristic of the suckling ; in the absence of further 

 evidence, we may perhaps accept the view that the young 

 are drawn to the mother by the sense of warmth, and 

 come in contact with the teats either as the result of 

 random movements and vague attempts to suck something 

 (other parts being often sucked as well as the teats), or in 

 response to stimuli affecting the sense of smell, or through 

 some external guidance. 



The suggestive value of smell is of great importance 

 both to animals of the hunting type, such as the dog or the 

 cat, and of the hunted type, such as the rabbit ; and it is 



