NATURAL SELECTION CRITICISED. 305 



faeces." " Hence this becomes afterwards a mark of 

 pleasure in them and in dogs, and in other tailed 

 animals." As for eats being different, " these animals 

 having collar bones use their paws like hands when they 

 suck, which dogs and sheep do not." Why cats purr, 

 is that they draw in their breath, which is a resemb- 

 lance to their manner of sucking. A smile, as we have 

 seen, is the expression of our first satiety. We jar our 

 teeth always when we hear certain sounds, from our 

 early biting of the cup or glass that was forced to our 

 lips with medicine ! 



It needs only a very cursory examination of the book 

 to assure us how very similar the grandson is to the 

 grandfather in precisely such like physical moralisations. 

 We have this (p. 46), for example: " Kittens, puppies, 

 young pigs, and probably many other young animals, 

 alternately push with their fore feet against the mammary 

 glands of their mothers, to excite a freer secretion of 

 milk, or to make it flow." This first instinctive service- 

 able action leads, by mere repetition, to the establish- 

 ment of that strange custom in cats to pound with their 

 fore paws any soft substance on which they may chance 

 to stand. 



This is a perfectly normal specimen of Mr. Darwin's 

 main doctrine in regard to expression. As one sees 

 without difficulty, there may of course be other inter- 

 pretations of the facts. Most people w.mld be inclined 

 to say that the movement of the paws in sucking was 

 simply an unmotived and spontaneous manifestation of 

 pleasure ; but it is at once to be noted that it is the 

 very character distinctive of Mr. Darwin, that He will 

 have no such unmotived action. That there was this 

 pawing on the part of kittens at first was not meaning- 

 less to him ; it was to push the milk, and hence the 

 subsequent custom. Ts this so certain ? Had a kitten, 



