INDEX 



725 



females in, 595, 596 ; limit of power 

 of, to reduce variability, 534-537 ; 

 natural selection always at work, 

 588 ; need of large numbers for, 584 ; 

 need of the actual test for, 586 ; 

 objects of, 579 ; often against vigor 

 and fertility, 583 ; physiological, 589 ; 

 power of, to modify type, 291, 537- 

 544; progressive, 197; purpose of, 

 581; rational, 592, 593; reduces to 

 utility basis, 591 ; results in absolute 

 increase of quality, 582 ; reversal of, 

 288; size in dam, quality in sire, 588 ; 

 the exceptional breeder not always 

 the exceptional individual, 585 ; upper 

 limits of improvement, 583 ; value of 

 the exceptional breeder, 585 ; visible 

 characters deceptive in, 508, 510. 



Selective death rate, 201, 202. 



Selective influence of environment, 35 1 . 



Sewall, experiments with snake poison, 



39- 



Sex, correlation with speed in trotters, 

 468-470 ; determination of, 629-637 ; 

 differences slight, 630 ; in mammals, 

 634 ; in bees, 632 ; in plant lice, 632 ; 

 in wasps, 633 ; influence of, upon 

 development of characters, 194-196; 

 influence of fertilization upon, 632, 

 633; influence of nutrition upon, 631; 

 inheritance not limited to, 474 ; re- 

 lated to the accessory chromosome, 



634-637- . 

 Sex determination, theories upon, 629, 



630. 

 Sexes, comparative variability of, 570, 



573; equipotent, 568. 

 Sharks, effect of light on eyes of dead, 



395- 



Sheep, development of foot of, 58 ; me- 

 ristic variation in digits of, 63. 



Shorthorns, polymorphism in, 20. 



Show-ring consequences, 660. 



Shy breeders, 119, 200. 



Sire, quality in, 588. 



Sire more than half the herd, 587. 



Sires, great, 552; market for, 673; of 

 sires and sires of dams contrasted, 

 553-555 : testing of, 662-664. 



Smoothing of figures, 690, 691. 



Snakes, rudimentary legs of, 58. 



Spallanzani, experiments in regenera- 

 tion, 316. 



Species, supposed conversion of, 283. 



Sperm cell, 161. 



Spermatocytes, 169. 



Spermatozoon, 161 ; function of, 281. 



Spinal nerves, meristic variation in, 42. 



Spireme, 146. 



Sports, 21, in. 



Stability, of type, 296, 297 ; shown 

 by reversion, 305 ; of living matter 

 illustrated by grafting, 335, 336 ; by 

 regeneration, 316-335. 



Stability and instability of living matter, 

 295-346 ; illustrated by development 

 and differentiation, 338. 



Standard deviation, 42^-431, 698-703, 

 as a measure of variability, 700 ; con- 

 trasted with average deviation, 431 ; 

 illustrated, 441-443 ; meaning of, 

 432, 433 ; probable error of, 440, 702, 

 703 ; shortened method of, 429. 



Standards should not be changed, 



579- 



Starvation, effects of, upon regenera- 

 tion, 327. 



Statistical methods, 426, 681-713 ; need 

 of, in heredity studies, 478, 68 1 ; 

 reliability of, 692. 



Stature, transmission 0^480-484, 488- 



493' 499-5 02 - 



Steers, functional variation in, 82. 



Stentor, acclimatization of, to HgCl2, 

 310; regeneration in, 323. 



Stereotropism, 250. 



Sterility of hybrids, 609. 



Sterling, originator of blackberry, 133. 



Stirp, 14, 152, 208. 



Strasburger, growth below zero, 313. 



Strawberry, evolution of, 131. 



Struthers. observations on ribs, 40. 



Stunted animals, 225. 



Substantive variation, 30-32 ; impor- 

 tance of, 31. 



Suprarenal glands, 383. 



Swine, development of foot of, 58; 

 inbreeding in, 625. 



Symmetry, 34-37 ; bilateral, 34, 65-68 ; 

 dorsal and ventral, as distinct from 

 right and left, 34-36 ; in variable parts, 

 68-70 ; longitudinal, 36 ; radial, 34. 



Syndactylism, 63, 66. 



Systems of breeding, 599-627. 



Tapir, development of foot of, 60. 



Teeth, meristic variation in, 48-51. 



Telegony, 185-189; in dogs, 186 ; in 

 horses, 185; in man, 188; proof by 

 method of instance, 187 ; scientific 

 objections to, 188. 



Teleology, principle not universal, 207. 



Temperature, acclimatization to, 311- 

 313,376-381; all-pervading, 264; effect 

 of, upon color, 262-264; upon growth, 

 254-262; upon parthenogenesis, 281; 



