340 AFFECTION OF INSECTS FOR THEIR YOUNG. 



select for them. But no: as if aware that this food 

 would be to them poison, she is in search of some 

 plant of the cabbage tribe. But how is she to distin- 

 guish it from the surrounding vegetables ? She is 

 taught of God! Led by an instinct far more unerring 

 than the practised eye of the botanist, she recognises 

 the desired plant the moment she approaches it, and 

 upon this she places her precious burthen ; yet not 

 without the further precaution of ascertaining that it is 

 not preoccupied by the eggs of some other butterfly ! 

 Having fulfilled this duty, from which no obstacle short 

 of absolute impossibility, no danger however threaten- 

 ing, can divert her, the affectionate mother dies. 



This may serve as one instance of the solicitude of 

 insects for their future progeny. But almost every 

 species will supply examples similar in principle, and 

 in their particular circumstances even more extraordi- 

 nary. In every case (except in some remarkable in- 

 stances of mistakes of instinct, as they may be termed, 

 which will be subsequently adverted to) the parent un- 

 erringly distinguishes the food suitable for her offspring, 

 however dissimilar to her own; or at least invariably 

 places her eggs, often defended from external injury by 

 a variety of admirable contrivances, in the exact spot 

 where, when hatched, the larvaB can have access to it. 

 — The dragon-fly is an inhabitant of the air, and could 

 not exist in Avater: yet in this element, which is alone 

 adapted for lier young, she ever carefully drops her 

 eggs. The larvai of the gad-fly (QLstrus Equi), whose 

 history has been before described to you% are destined 

 to live in the stomach of the horse. How shall the pa- 



* P. 147 &c. 



