OBJECTIONS ANSWERED. 53 



are not indigenous, but have been imported. It was thus that the moth 

 (Galleria Mellonella) so destructive in bee-hives, and the asparagus beetle 

 l^Crioceris Asparagi), were made denizens of Sweden.^ The insect that 

 has destroyed all the peach trees in St. Helena was imported from the 

 Cape ; and at home (not to mention bugs and cock-roaches) the great 

 pest of our orchards, before mentioned, the apple Aphis, there is good 

 reason to believe, was introduced with some foreign apple-trees. Now, 

 extensive as is our commerce, it is next to impossible, by any precautions, 

 to prevent the importation 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 intro- 

 duced, 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 specula- 

 tions 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 fertilize 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 uneasi- 

 ness occasioned, by what are called vulgar errors, and that superstitious 

 reliance 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.^ Nine larvae of the moth of the wild 

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

 ague.^ Matthiolus gravely affirms that every oak-gall contains either a fly, 

 a spider, or a worm ; and that the first foretells war, the second pestilence, 

 and the third famine.'* 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 circum- 

 stance 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 BemdrJcelse-masJc, or prognostic worm.^ 



» Fn. Suec. 567. 1383. 2 Amoreux, 276. » Rai. Cat. Cant. 45. Hist. Ins. 341. 



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



* De Geer, iv. 275, 276. 



5* 



