342 AFFECTION OF INSECTS FOR THEIR YOUNG. 



dinary. Flying round the animal, she curiously poises 

 her body for an instant while she glues a single egg to 

 one of the hairs of his skin, and repeats this process 

 until she has fixed in a similar way many hundred eggs. 

 These, after a few days, on the application of the slight- 

 est moisture attended by warmth, hatch into little grubs. 

 Whenever, therefore, the horse chances to lick any part 

 of his body to which they are attached, the moisture of 

 the tongue discloses one or more grubs, which adhering 

 to it by means of the saliva are conveyed into the mouth, 

 and thence find their way into the stomach. But here 

 a question occurs to you. It is but a small portion of 

 the horse's body which he can reach with his tongue : 

 what, you ask, becomes of the eggs deposited on other 

 parts ? I will tell you how the gad-fly avoids this di- 

 lemma ; and I will then ask you if she does not discover 

 a provident forethought, a depth of instinct, which al- 

 most casts into shade the boasted reason of man ? She 

 places her eggs only on those parts of the skin which the 

 horse is able to reach with his tongue ; nay, she confines 

 them almost exclusively to the knee or the shoulder, which 

 he is sure to lick. What could the most refined reason, the 

 most precise adaptation of means to an end, do more a ? 

 Not less admirable is the parental instinct of that vast 

 tribe of insects already introduced to you by the name 

 of Ichneumons, whose young are destined to feed upon 

 the living bodies of other insects. These, as you know, 

 are so numerous, that scarcely an insect exists, which in 

 its larva state is not exposed to the attacks of one or 

 other of them ; and even the pupae, nay the very eggs of 

 these animals, are not safe from their insidious manceu- 

 a Clark in Linn. Trans, iii. 304. 



