1)0 THE SIMPLER ANIMALS FEEL PAIN? 331 



violent agony, yet he will tell us that, so far from feeling 

 any uneasiness, he was totally unconscious of having been 

 touched. A decapitated frog manifests the same movements 

 of self-preservation as it manifested when its head was on. 

 When engaged in certain fmictions, his leg may be cut off' 

 without causing him to desist. An insect will sometimes 

 continue eating if pinned to the table, and will only struggle 

 to fly away when the food is devoured. " Soft, lubricated, 

 and irritable as is the skin of the naked mollusc," says 

 Professor Owen, " there are not wanting reasons for suppos- 

 ing it to be possessed of a very low degree of true sensibility. 

 Baron Perussac, for example, states that he has seen the 

 terrestrial gasteropods, or slugs, allow their skins to be 

 eaten by others, and in spite of the large wounds thus pro- 

 duced, show no sign of pain."* But even if they showed 

 "signs" of pain, we might legitimately question whether 

 those signs really signified what they seem to us to indicate. 

 Nothing can be concluded from struggles, shrinkings, and 

 cries. A decapitated man, in whom all consciousness is 

 necessarily obliterated, struggles to free his hands, attempts 

 to stand upright, and stamps with his feet. A headless fly, 

 fish, or worm, writhes and twists about if touched, although 

 entirely deprived of sensation ; a fly makes the movement 

 of brushing its eyes by reflex action, although its head may 

 be off". Animals that fight with their hind-legs use them 

 vigorously when decapitated, at every ii-ritation applied to 

 the nerves. Headless insects deposit their eggs with as 



* Owen : Led. on Comparative Anatomy, p. 551. 



