INDEX. 535 



F 



Fallow-deer. His artifices and manners, 401. 



Farina. See plants and fexes. Farina of flowers the raw material of wax, 339. 



Feelers of infefts. One ufe of them, 84. 



Females. See fexes, man, and males. Among infefts, great differences between 

 males and females, 239, 240, 241. Female birds of prey larger, ftronger, and more 

 beautiful than the males, 241. The reverfe takes place among gallinaceous birds, 

 242. Changes in body and mind produced by puberty, 265. Arrive fooner at that 

 period than males, 265. 



Fire-fly. Emits a fliining light in the night, 91. 



Fifhes. Sketch of their ftrufture, 77. Much diverfified in figure, 78. Are endowed 

 with the fenfe of hearing, 80. Their mode of refpiration, 1 16. Analogy between 

 them and birds, 117. We are ignorant of the periods when they become fit for 

 multiplying, 267. Cruftaceous kinds caft their fliins annually, 290. The life of 

 every fi£h one continued fcene of hoftility, 382. Shell-fifhes very prolific, 396. 

 Their artifices, 410. Of their migration, 495. Their longevity, 509, 513. 



Flea. A defcription of it, 97. Undergoes a transformation like that of winged in- 

 fefts, 98. 



Flies. See infefts. An account of the phrygania or fpring-fly, 94. Of the dragon- 

 fly, ibid. Of the cinyps, the eggs of which give rife to the galls on oak leaves, ibid. 

 Gad-fly very troublefome to cattle, 96. Of the common fly, ibid. Of the gnat, 

 ibid. Spider-fly as large as the mother when it efcapes from the egg, 222, 296. 

 Some depofit their eggs in the leaves of plants, ibid. Ichneumon flies deftrudlive to 

 bees, 329; and other infefts, 383. 



food of plants and of animals compared, 25. Man could not live upon herbage alone, 

 60. Food neceflliry for the growth and expanfion of all organifed beings, 208. See 

 growth. The general ingredients of food, 215. Rein-deer, the principal food of 

 the Laplanders, ibid. ■ Animal food more ufed in proportion as people recede from 

 the Equator, 216. The nature of man's food determined by the climate, 217. Man 

 defigned by Nature to feed partly on animal and partly on vegetable fubftances, ibid. 

 218. Living long on a particular fpecies of food is apt to create difeafes, 219. Diver- 

 fity of food ufed by different fpecies one caufe of the diffufion of animals over the 

 earth, 220. Every animal furnifhed with proper infl;ruments for procuring food, 

 221. Importance of feeding all young animals well, 223. Infedls which feed upon 

 carrion never attack live animals, 223. This faft eftabliflied by experiments, 223, 

 224. Spalanzani's experiments upon the digeftion of food by various animals, 225. 



Foramen ovale. In amphibious animals it remains open during life, 66. 



rormica-leo. Its artifices and manners, 411. 



Forms 



