410 



INDEX 



of. 77-78 ; classification of, 161-163 ; 



origin of, 176. 

 Reservoir of nervous system, 300. 

 Respiration, organ of, as indicating 



natural affinities, 31 ; physiology of, 



268-271. 

 Richerand, on the erect position of man, 



172 ; on the characters of life, 194 ; 



his definition of life, 201 ; on sensation, 



329. 

 Rotifers, 203. 



Scale of animals, 68 ; regularity of, 70. 



Sea-anemones, nervous system of, 138. 



Seals, affinities of, 173 ; hind legs of, 174 ; 

 habits of, 174. 



Sensation, mechanism of, 322 et seq. ; the 

 origin of ideas, 363. 



Sensorium commune, site of the, 294. 



Sexual reproduction, not found lower than 

 insects, 93 ; nature of, 241-242 ; ab- 

 sent in primitive animals, 245 ; and in 

 cryptogams, 268 ; a special faculty, 

 274. 



Sight, not found lower than insects, 95. 



Sipunculus, 140. 



Skill, in animals, 353 ; only found among 

 vertebrates, 354. 



Skin, origin of, 232. 



Sleep, nature of, 341. 



Sloth, 125. 



Snakes, why they have no legs, 78, 117. 



Soul, our ignorance of the, 294. 



Sound, substance of, 116 (note). 



Spallanzani, his rotifer, 203. 



Species, definition of, 35 ; belief in per- 

 manency of, 35-36 ; merge into one 

 another, 37 ; transformation of, 39 ; 

 not affected by Geoffrey's collections, 

 40 ; extinction of, 44 ; constitute a 

 linear series, 58. 



Speech, origin of, 173 ; value of, 378. 



Spinal cord, function of, 298. 



Spontaneous generation, conditions for, 

 237 ; reality of, 238 ; when it occurs, 

 244 ; where it occurs, 246 ; necessity 

 for, 248. 



Spurzheim, see Oall. 



Star-fishes, nervous system in, 138. 



Sublime Author of the Universe, see God. 



Subtle fluids, movements of, 188 ; ubi- 

 quity of, 212 ; constitute the exciting 

 cause of organic movements, 213 ; 

 produce animal movements, 344. 



Synonymy, evils of, 27. 



Systems naturae, 63. 



Teeth of whales, loss of, 115. 



Tenon, on the effects of drink, 118. 



Thought as an intellectual faculty, 384- 

 388. 



Torpidity, in animals, cause of, 222-223. 



Tracheae, description of, 270. 



Tracy, de on ideas, 373. 



Triticum sativum, a product of cultiva- 

 tion, 109. 



Understanding, see Intelligence. 



Use, effects of, 119 ; see also Inheritance 



of acquired characters. 

 Use-inheritance, see Inheritance of acquired 



characters. 



Vertebral column, annihilation of, 81. 

 Vertebrates, first recognised, 62 ; degra- 

 dation of, 81. 

 Vital force, 251. 

 Vital principle, absurdity of, 212. 



Walruses, habits of, 174 ; lead to ungu- 

 lates, 177. 



Whales, loss of teeth by, 115. 



Wheat, see Triticum sativum. 



Will, nature of the, 355 ; conditioned by 

 intelligence, 356 ; based on nervous 

 system, 357 ; confined to vertebrates, 

 358 ; freedom of the, 360 ; of secondary 

 importance, 380. 



Woodpecker, its tongue, 120. 



Worms, definition of, 95 ; classification of. 

 140-141 ; give rise to insects, 176. 



Zoophyte an improper term, 51, 200. 



