OBJECTIONS ANSWERED. 17 



orchards, before mentioned, the apple Aphis, there is good reason to believe 

 was introduced with some foreign apple-trees. JNow, extensive as is our 

 commerce, it is next to impossible, by any precautions, to prevent the im- 

 portation of these noxious agents. A cargo of wheat from North America 

 might present us with the famed Hessian fly, which some years ago caused 

 such trepidation in our cabinet ; but though introduced, the presence of 

 these insects, were Entomology a more general pursuit, would soon be 

 detected, and the evil at once nipt in the bud ; whereas in a country where 

 this science was not at all or little cultivated, they would most probably 

 have increased to such an extent before they attracted notice, that every 

 effort to extirpate them would be ineffectual. 



It is needless to insist upon the importance of the study of insects, as 

 calculated to throw light upon some of the obscurest points of general 

 physiology ; nor would it be difficult, though the task might be invidious, 

 to point out how grossly incorrect and deficient are many of the speculations 

 of our most eminent philosophers, solely from their ignorance of this 

 important branch of Natural History. How little qualified would that 

 physiologist be to reason conclusively upon the mysterious subject of gene- 

 ration, who should be ignorant of the wonderful and unlooked-for fact, 

 brought to light by the investigations of an entomologist, that one sexual 

 intercourse is sufficient to fertilise the eggs of numerous generations of 

 Aphides ! And how defective would be all our reasonings on the powers 

 of nutrition and secretion, had we yet to learn that in insects both are in 

 action unaccompanied by the circulating system and glands of larger 

 animals ! 



In another point of view entomological information is very useful. A 

 great deal of unnecessary mischief is produced, and unnecessary uneasiness 

 occasioned, by what are called vulgar errors, and that superstitious re- 

 liance upon charms, which prevents us from having recourse to remedies 

 that are really efficacious. Thus, for instance, eating figs and sweet things 

 has been supposed to generate lice. 1 Nine larvae of the moth of the wild 

 teasel enclosed in a reed or goose quill have been reckoned a remedy for 

 ague. 2 Matthiolus gravely affirms that every oak-gall contains either a 

 fly, a spider, or a worm ; and that the first foretells war, the second pes- 

 tilence, and the third famine. 3 In Sweden the peasants look upon the 

 grub of the cock-chafer as furnishing an unfailing prognostic whether the 

 ensuing winter will be mild or severe ; if the animal have a bluish hue (a 

 circumstance which arises from its being replete with food) they affirm it 

 will be mild, but, on the contrary, if it be white, the weather will be severe : 

 and they carry this so far as to foretell, that if the anterior part be white 

 and the posterior blue, the cold will be most severe at the beginning of 

 the winter. Hence they call this grub Bem'drkelse-mask, or prognostic 

 worm. 4 A similar augury as to the harvest is drawn by the Danish pea- 

 sants from the mites which infest the common dung beetle (Geotrupes 

 stercorarius), called in Danish Skarnbosse or Torbist. If there are many of 

 these mites between the fore feet, they believe that there will be an early 



1 Amoreux, 276. 



2 Rai. Cat. Cant. 45. Hist. Ins. 341. 



3 Comment, in Dioscor. 1. 1. c. 23. 214. Lesser L. ii. 280. 



4 De Geer, iv. 275, 276. 



c 



