OBJECTIONS ANSWERED, 17 
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 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 ate 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.!_ 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 pes- 
tilence, and the third famine.8 In Sweden the peasants look upon the 
gtub 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 Bemiirkelse-mask, or prognostic 
worm.* 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 ave many of 
these mites between the fore feet, they believe that there will be an early 
1 Amoreux, 276, 
2 Rai. Cut. Cant. 45. Hist. Ins. 841. 
5 Comment. in Dioscor. 1. 1, c. 28. 214, Lesser LZ, ii. 280, 
* De Geer, iv. 275, 276. 
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