vi INSTINCT 69 



eggs in the flowers of the carrion plant, the smell of which 

 resembles that of' putrid meat. 1 No case of this kind is 

 more wonderful than that of the Sitaris beetle, 2 the larva 

 of which begins life by attaching itself to a bee which has 

 afterwards to provide for it. Does one ask how the larva 

 knows the bee ? The reply is, it does not. 



" Although they are close to the abodes of the bees they do 

 not enter them, but seek to attach themselves to any hairy object 

 that may come near them, and thus a certain number of them 

 get on to the bodies of the Anthophora and are carried to its nest. 

 They attach themselves with equal readiness to any other hairy 

 insect, and it is probable that very large numbers perish in con- 

 sequence of attaching themselves to the wrong insects." 3 



These and similar instances go to show that what guides 

 the larva or the fly is no unerring internal or external 

 guide, but the contact of the hairs, the smell of the meat. 

 The mechanism of the instinct consists in this : that at the / 

 time when the fly is ready to lay the eggs, the smell (or) 

 the diffused chemical stimulus which, for us, is a smell); 

 attracts the fly, and contact with the smelling substance^' 

 gives the final touch which sets the process of laying t^ 

 work. Similarly the cuttlefish at the due season has thb 

 impulse to embrace its mate. Here the stimulus appears 

 to be the shape of the mate, for a piece of wood appro- 

 priately shaped will be so violently and persistently 

 embraced that it can be used as a bait with success. 4 A 

 tame dove will give the instinctive sex reactions to the 

 most inappropriate object, bowing and cooing ludicrously 

 to a shoe or to the hand of the owner, behaving in per- 

 fectly characteristic fashion, but with complete ineptitude. 5 

 Similarly a young hawk strikes a harmless piece of meat 

 with ruffled feathers, spread wings, and savage thrust of 

 beak and claw, in fine with all the instinctive adaptations 

 and expressions appropriate to the pounce on living prey, 

 in response to some stimulus of odour or touch, but 

 quite fruitlessly for the purpose in hand. 6 



1 Romanes, M.E.A. p. 167. Cf. Schneider, Der thierische Wille, 

 p. 268. 2 Lloyd Morgan, Habit and Instinct, pp. 15, 304. 



3 The Cambridge Natural History, VI. p. 272. 



4 Schneider, Der thierische Wille, p. 1 73. 



5 Craig, Male Doves reared in Isolation, J.A.B. 1914, pp. 123, 132, c. 



6 Haggerty, A Case of Instinct, J.A.B. 1912, p. 79. 



