54.0 INDEX. 



affected by cold than at any other period, 207. Theif 

 lives very precarious, ibid. Caufes of their difeafes and 

 mortality, 208. Sleep, for feveral weeks, almoft conti- 

 nually, 208. Their memory weak, and why, 209. Du- 

 ration of infancy in different animals, 210. Infant ftate 

 of birds lliort, 211. Infancy of fiflies, ibid. Of infe6ts, 

 ibid. The ftrong attachment of parents to their young, 

 212. 



Infe(Si:3. A fketch of their fl:ru(flure, 26, 27. A more en- 

 larged view of it, 92. Diviiion of infects from their wings, 

 93. Ufe of their feelers, 94^. Undergo three changes of 

 form, 97. Some of them endowed with the fenfe of fmel- 

 ling, 97 5 and fome probably v;ith that of hearing, 97. Ac- 

 count of their probofcis, 98. Of the form and manners 

 of the beetle tribe, 99. Of the form and manners of the 

 hemipterous tribe, 99. Of neuropterous infects, 102. Of 

 hymenopterous infecb, 103. Of dipterous infedls, 105. 

 Of apterous infects, 106. Of the refpiration of infecSts, 127. 

 Examples of their infkin^ts, 155. Infects have few in- 

 ftincls, 162. Thofe that feed upon carrion, never attack 

 live animals, 228. Great differences between fome male 

 and female infedts, 243, 244, 245. Defcription of the 

 form and manners of gall-infe(5ls, 245. Infe(n:8 fuppofed 

 to impregnate certain plants, 254. Changes they under- 

 go before their age of puberty, 271. Some of them have 

 a ftrong affection to their young, 277. Of their transfor- 

 mations, 295. Lives of winged infe<Sts conlifts of three 

 principal periods, 298. Their internal parts changed after 

 transformation, 298. The behaviour of different caterpil- 

 lars when about to transform, 303. Their transforma- 

 tion is only the throwing off temporary coverings, 305. 

 Nefts of various infects defcribed, 330. Some of them 

 are rapacious, 287. Thoufands of them daily devoured 

 by cattle, 394. Infedts afford many inftances of affocia- 

 tion, 425. Some of them migrate, 505. Are fhort lived, 

 517. 



Infpiration. See refpiration. 



InftincTt. Reafons why it has been fo little underftood, 153. 

 Divifion of inll:in6ts, 153. Of pure inftinOs, 154, Exam- 

 ples of it in the human fpecies, ibid. *, in the brute crea- 

 tion, 155. Of inftindts which can accommodate them- 

 felves to peculiar circumftances, 158. Of inilindts which 



