594 
Spencer, H., on the transmission of ac- 
quired characters, 139 
— on Weismann, 33, 140 
— 38, 14, 305, 461, 467, 482, 497 
Sphingidae, variation in, 28 
Spinoza, 142, 453 
Sports, 69, 73, 181 
Sprengel, C. K., 4, 403-405, 409, 420 
Stability, principle of, 543-554 
Stahl, 397 
Standfuss, 62, 258 
Stars, evolution of double, 543-546 
Stellaria media, 421 
Stephen, L., 461 
Sterility in hybrids, 97-99 
Sterne, C., 7? 
Stockard, his experiments on fish embryos, 
255 
Srraspurcer, E., on The Minute Structure 
of Cells in relation to Heredity, 102-111 
Strongylocentrotus franciscanus, 249 
S. purpuratus, 249, 252, 254 
Struggle for existence, 19, 20, 77, 78, 471- 
473 
Strutt, R. J., 578 
Stuart, A., 369 
Sturdee, F. C. D., 370 
Siitterlin, L., 5161 
Sully, 123 
Sutton, A. W., 99! 
Sutton, W. S., 1091 
Sval6f, agricultural station of, 80-83 
Swainson, W., 320, 324 
Synapta, calcareous bodies in skin of, 
29-32 
S. lappa, 30 
Syrphus, 57 
Tarde, G., 476 
Teleology and adaptation, 272-274 
Tennant, F. R., 480! 
Teratology, 66 
Tetraprothomo, 132, 136 
TuisELToN-Dyer, Sir Wuinu1am, on Geo- 
graphical distribution of Plants, 298-318 
— on Burchell, 274! 
— on protective resemblance, 276? 
— 275 
Index 
Tooke, Horne, 516 
Totemism, 160-169 
Treschow, 449 
Treviranus, 8, 12, 13, 319, 320 
Trifolium pratense quinquefolium, 244 
Trigonias, 193 
Trilobites, phylogeny of, 199 
Tschermack, 242, 418? 
Turgot, 532 
Turner, Sir W., 140 
Twins, artificial production of, 254, 255 
Tylor, 467, 497, 498, 502 
Tyndall, W., 482 
Tyrrell, G., 482? 
Uhlenhuth, on blood reactions, 129 
Underhill, E., 510! 
Use and disuse, 22, 32-34, 37-42, 89, 90, 
118, 139 
Vanessa, 48 
V. antiope, 264 
V. levana, 23, 24, 258 
V. polychloros, 62 
V. urticae, 50, 62 
Van ’t Hoff, 256 
Varanus Salvator, 317 
Variability, Darwin’s attention directed to, 
19 
— W. Bateson on, 85-101 
— and cultivation, 245, 246 
— causes of, 74-77, 225, 448 
— polymorphic, 77-84 
Variation, continuous and discontinuous, 
238, 239 
— Darwin’s views as an evolutionist, and 
as a systematist, on, 457 
— definite and indefinite, 224, 225 
— environment and, 224, 235-237 
— and heredity, 84-101, 242 
— as seen in the life-history of an or- 
ganism, 179-182 
— minute, 21-25 
— mutability and, 179-182 
— in relation to species, 69, 94, 95 
— H. de Vries on, 66-84 
Varigny, H. de, 7, 16 
Varro, on language, 513 
THomson, J. A., on Darwin’s Prede 3, 
3-17 
— 140 
— and P. Geddes, 473 
Thomson, Sir J. J., 568, 571, 581, 582 
Theology, Darwin and, 477 
Tiedemann, F., 319 
Ver chamaedrys, 243, 245 
Verworn, 130 
Vestiges of Creation, Darwin on The, 13 
Vierkandt, 5064 
Vilmorin, L. de, 245 
Virchow, his opposition to Darwin, 145, 
146 
