INDEX. 



451 



Symmetry, radial, 291. 

 Swan, 313. 



Tail, of kang-aroo, 318. 



Teeth, 307 ; atrophy of, 307 ; in embryo 



birds, 307 ; in whales, 307. 

 Temperature, 410. 

 Tentacles of snail, 348, 354. 

 Tertiary shells, no, 125, 133. 

 Thought, definition of, 172. 

 Time, geological, 119, 130, 222, 236. 

 Toes, modifications of, 234, 311, 315, 317, 



321, 338, 344. 

 Tree, genealogical, first, 130, 181, 192, 



193. 349. 

 Trout, 403. 



Tubercles, origin of, 394. 

 Tunicata, position of, 195. 

 Turbot, 314. 

 Turtle, sea, 312. 



Uniformitarianism, 130, 



Use, 248, 256, 257, 302, 303, 311, 318, 384, 



412. 

 Use-inheritance, 219, 224, 246^ 276, 303, 



3191 346. 



Use originates organs, 276, 311, 346. 



Variability, 407. 



Variation, climatic, 204, 218, 401 ; causes 



of, 2t8, 266, 

 Varieties, 401. 

 Varigny, H. de, 408. 

 Vestigial organs, 307, 308. 

 Vital force, 167. 

 Vitalism, 168. 

 Volucella, 338. 



Wagner, M., 404. 



Wallace, A. R., on origin of giraffe's 



neck, 351. 

 Wants, 245, 270, 274, 281, 295, 302, 324, 



334. 346, 350, 3511 352- 

 Ward, L. F., 422. 



Water, diversified condition of, 290. 

 Werner, 97. 

 Whale, 307, 343, 409. 

 Will, 319, 330, 337. 

 Willing, 236, 351, 412. 

 Weismann, A., 399. 

 Wings, atrophy of, in insects, 309. 

 Woodpecker, 313. 



