INDEX. 64:1 



arc improveable by experience and obfervatlon, 160, 161, 

 Superiority of man anfes from iiis great number of in- 

 llincls, 160. ^Examples of modi lied, compounded, or ex- 

 tended inftincts, 161. Inftindl defined and explained, 162. 

 Infects have few inftia^ls, ibid. Inftin^t prel'uppofes a de- 

 gree of intelle^, 4'25. The gradual progrefs of inftinc^s in. 

 children, 439. When they begin to reafon with fome 

 propriety, 440. The education of animals depends greatly 

 on the principle of imitation, 473. 



Irritability defcribed, 20. Many plants are endowed with 

 this power, 20. 



L 



Lady-fly. See libella. 



Language. Mod animals can exorefs their wants and de- 

 Hres, 118, 164, 179. Artificial a refult of natural lan- 

 guage, 179. The origin of the great diverfity of lan- 

 guages, 180. Articulate language peculiar to man, 420. 

 Laplanders. Live chieiiy on the rein-deer, 221. Fond of 

 bear's iieQi, ibid. 



Laughing defcribed, 118. Not peculiar to man, ibid. 



Leggs. No animal, except the infe6l tribes, have more 

 than four, 93. 



Libella. A defcription of it, 102. Its nymph refpires 

 water, 130. A rapacious animal, 388. 



Life. Our ignorance of its elTential characleriftics, 19. Its 

 duration longer or fhorter according to the fpecies, 49. 

 Life very precarious in infancy, 207. Lives of winged 

 infects conlift of three principal periods, 298. Life can- 

 not be fupported without the intervention of death, 392. 



- A profuiion of animal life feems to be a general intention 

 ot Nature, 396. Of the duration of life in mian and other 

 animals, 506, &c. Its duration a relative idea, 520. 



Light. Some of its properties, 186. Its refrangibility, 187. 



Lobfters caft their Ihells annually, 294. 



Longevity of animals, 506. Some remarkable inftances of 

 it in the human fpecies, 508.; of lifhes, 51 1, 515. ; of 

 quadrupeds, 513; of a toad, 516; of infects 517; of plants, 

 518. 



Loufe. Its ftrudturc and manners, 106. 



Love. The fource of many important advantai:::es ; 274. 

 Is a great incentive to virtue, 274, ibid. Bad effe<5fs of too 

 early marriages, 275 ; and of imprudent ones, 276. Love of 

 U uu 



