388 NATURAL HISTORY OF AQUATIC INSECTS CH. 



triumphs of human science, were long ago turned 

 to practical account by some of the most insignifi- 

 cant of Insects. Many of these natural contrivances 

 secure the safety, and increase the happiness of 

 living creatures. But there is a dark side to the 

 picture. 



In the Theodicees and Natural Theologies, which 

 now fill whole libraries, we shall find little mention 

 of the murderous instincts of animals, or of the 

 cruel weapons which are placed at their service/ Yet 

 the ravages of carnivorous Quadrupeds, Birds, and 

 Insects are as obvious as any of the operations of 

 nature. The misery caused by internal parasites 

 is less conspicuous, but even more perplexing. The 

 Dragon-fly and the Dytiscus are not altogether 

 pleasing objects of contemplation, but the Ichneumons 

 seem to go beyond all that the cruelty of despots 

 has imagined. That innumerable Insects should be 

 eaten up alive by parasites, which spare the vitals of 

 their victims lest they should perish too soon, that 

 this miserable existence should be protracted until 

 pupation, so that the devourer should find a safe 

 shelter during its own resting-stage these are facts 

 which show us that Nature is not everywhere bene- 

 ficent. Of the same kind are the facts related con- 

 cerning some of the fossorial Hymenoptera. I can 

 never read Fabre's Souvenirs Entomologiques without 

 a shudder. The operations which he has brought to 

 light with such diligence, and described with such 

 animation, impress me much as do the tales told of 

 the Well of Cawnpore or the Ice-tower of Avignon, 

 What may be the solution of the mystery, and how 



