INDEX. 
Symmetry, radial, 291. 
Swan, 313. 
Tait, of kangaroo, 318. 
Teeth, 307 ; atrophy of, 307; in embryo 
birds, 307 ; in whales, 307. 
Temperature, 410. 
Tentacles of snail, 348, 354. 
Tertiary shells, rro, 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, 
319, 346. 
451 
Use originates organs, 276, 311, 346. 
VARIABILITY, 407. 
Variation, climatic, 204, 218, 401 ; 
of, 218, 266. 
Varieties, gor. 
Varigny, H. de, 408. 
Vestigial organs, 307, 308. 
Vital force, 167. 
Vitalism, 168. 
Volucella, 338. 
causes 
Waane_er, M., 404. 
Wallace, A. R., on origin of giraffe’s 
neck, 351. 
Wants, 245, 270, 274, 281, 295, 302, 
334) 346, 350, 351, 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. 
324, 
