280 DARWINISM STATED BY DAEWIN HIMSELF. 



suddenly hearing that a large fortune had been bequeathed 

 to him. 



The imagination is sometimes said to be 

 tickled by a ludicrous idea ; and this so-called 

 tickling of the mind is curiously analogous with that of 

 the body. Everyone knows how immoderately children 

 laugh and how their whole bodies are convulsed when 

 they are tickled. The anthropoid apes, as we have seen, 

 likewise utter a reiterated sound, corresponding with our 

 laughter, when they are tickled, especially under the arm- 

 pits. I touched with a bit of paper the sole of the foot 

 of one of my infants, when only seven days old, and it 

 was suddenly jerked away and the toes curled about, as 

 in an older child. Such movements, as well as laughter 

 from being tickled, are manifestly reflex actions; and 

 this is likewise shown by the minute unstriped muscles, 

 which serve to erect the separate hairs on the body, con- 

 tracting near a tickled surface. Yet laughter from a 

 ludicrous idea, though involuntary, can not be called a 

 strictly reflex action. In this case, and in that of laugh- 

 ter from being tickled, the mind must be in a pleasura- 

 ble condition ; a young chiFd, if tickled by a strange man, 

 would scream from fear. The touch must be light, and 

 an idea or event, to be ludicrous, must not be of grave 

 import. The parts of the body which are most easily 

 tickled are those which are not commonly touched, such 

 as the armpits or between the toes, or parts such as the 

 soles of the feet, which are habitually touched by a broad 

 surface ; but the surface on which we sit ofEers a marked 

 exception to this rule. 



The sound of laughter is produced by a 



° ' deep inspiration followed by short, interrupted, 



spasmodic contractions of the chest, and especially of the 



