CH. XXIII.] HINTS FOR STUDENTS. 299 



of insects, from the supposed cruelty which entomol- 

 ogists are said to commit by taking the lives of a 

 few individuals for the purpose of placing them in 

 drawers, the object of which is to form, when they 

 are placed side by side, an idea of their variations, 

 and of the surprising differences which they exhibit. 

 "Cruelty," say Messrs. Kirby and Spence, "is an 

 unnecessary infliction of suffering, when a person is 

 fond of torturing or destroying God's creatures from 

 mere wantonness, with no useful end in view; or 

 when, if their death be useful and lawful, he has re- 

 course to circuitous modes of kiUing them, where 

 direct ones would answer equally well." 



This charge of cruelty is not brought against 

 sportsmen or anglers, &c., whose only object is to 

 add to the general stock of food in their larders ; 

 while the entomologist's object is to add to the gen- 

 eral stock of mental food, and, at the same time, to 

 endeavour to discover, for the benefit of the world in 

 general, the means of destroying the many species 

 of insects which are very injurious to our gardens, 

 and more especially to our fields. The total failure 

 of a crop of turnips in Devonshire, in 1786, was not 

 less in value than jC100,000 ; would it not therefore 

 be worth while to find out a remedy for an evil of 

 such enormous magnitude ? In the first place, it 

 becomes necessary, in such a case, to ascertain 

 which of the several insects that have attacked the 

 crop, whether the Haltica nemorum, termed by the 

 farmer the turnip-fly, or black jack, Centorhynchus 

 contractus, or the black larva of a sawfly, or the cater- 

 pillar of the cabbage butterfly, is the true cause of the 

 mischief, as each of these various kinds of insects 

 is different in habits, and in its modes of destroying 

 the turnip. When this knowledge is obtained, a 

 remedy can much better be proposed; but only 

 then, it must be allowed, by one who understands 

 the subject, or, in other words, by an entomologist. 



Their ravages on other vegetables afford many 



