726 



INDEX 



upon regeneration, 327 ; of the body, 

 230. 



Ten great sires, 555. 



Teratology, 100. 



Testing sires and dams, 660-664. 



Testing young females, 66 1. 



Tetrads, 166. 



Thigmotaxis, 235. 



Thremmatology, compared with evolu- 

 tion, 2 ; defined, I ; more than a study 

 in morphology, 8; problems of, out- 

 lined, 3-5. 



Thyroid, effect of extirpation of, 383. 



Toadflax, experiments with, by De Vries, 

 115-118. 



Toxic poisons, 268. 



Transmission, 347417 ; heterogeneous, 

 426; how characters behave in, 473 

 478; manner of, 420-431; effect of 

 acclimatization upon, 374-380 ; effect 

 of development upon, 407-409 ; of 

 disease, 368, 384 ; of effects of food, 

 370-374; of effects of use and dis- 

 use, 404-407 ; of habits, 386-403 ; of 

 immunity, 3^2; of mutilations, 364- 

 368 ; of stature, 480 ; of variation, 

 348-417 ; not unless germ is affected, 

 416, 417; offspring not like parents, 

 482, 483 ; offspring more mediocre 

 than the parents, 484-486 ; origin of 

 the exceptional individual, 499, 500 ; 

 progression in, 492-498 ; what is 

 transmitted, 511. 



Trembley, experiments on regeneration, 

 3,6. 



Trotters, correlation between color, 

 sex, and speed, 468-471. 



Trotting records showing prepotency, 



SSJ-S 66 - 



Tumors, 99, 271. 



Turtle, double head of, 67. 



Twins, 176; identical, 176; from a sin- 

 gle ovum, 176. 



Type, as distinct from the individual, 

 352; conceptions of, 420-425; effect 

 of environment upon, 290-293 ; ef- 

 fect of fertility upon, 198, 199, 449- 

 451 ; effect of selection upon, 445, 

 446 ; mutability of, 298-305 ; natural, 

 422 ; power of selection to modify, 

 537-544 ; selection standard for, 420, 

 425; stability of, 296, 297, 541, 544. 



Type and variability, 419-451. 



Use a function of structure, 387. 

 Use and disuse, effect of, 285-290; ef- 

 fect of, upon -functional activity, 95, 



96; effects of, when transmitted, 404- 

 407 ; influence on transmission, 363. 



Variability, among offspring of same 

 parents, 500-504 ; as affected by fer- 

 tility, 449-451 ; coefficient of, 433 ; de- 

 termined from groups, 426 ; deviation 

 from type, 425; effect of selection 

 upon, 445, 446 ; erroneous concep- 

 tions of, 425, 426; highest in fertile 

 soils, 642 ; in heights of brothers, 

 501; in oil and protein, 445, 446; 

 in physical characters of corn, 447, 

 ' 448 ; limitations of, 8, 9 ; limit to the 

 reduction of, 534-537 ; measure of, 

 by average deviation, 427 ; measure 

 *of, by standard deviation, 428-431 ; 

 nature of, 10, n ; of different char- 

 acters in same population, 444 ; of 

 sexes, 570-573; ultimate unit of, 

 15-17; units of, 208-213. 



Variation, bud, 181 ; causes of, 141- 

 347 ; caused by bisexual reproduc- 

 tion, 160-163 ; caused by cell division, 

 155-181 ; caused by external influ- 

 ences, 220-293; caused by reduc- 

 tion process, 163-181, causes of, 

 must be studied, 141 ; confined to 

 racial characters, 358 ; continuous 

 and discontinuous, 18-22; correlated, 

 16; does not extend to non-living 

 matter, 23 ; due to age or staleness 

 of germ, 182; due to temperature, 

 262-264; functional, 75-109; func- 

 tional, due to age, 94 ; functional, 

 between different individuals of the 

 same species, 77-91 ; functional, due 

 to use or disuse, 95, 96 ; functional, 

 from day to day, same individual, 

 91-94; functional, induced by ex- 

 ternal influences, 98, 101-105; func- 

 tional, influenced by feed, 96, 97 ; 

 how far possible, 29=5-346; induced 

 by food, 225-230; influence of mois- 

 ture upon, 230-233; influenced by 

 fertility, 196-200; influenced by the 

 reproductive functions, 100; influ- 

 enced by slight chemical changes, 

 210, 2ii ; in chemical composition of 

 seeds, corn, 8^-86 ; in fertility, 90 ; 

 in general body faculties, 86; in meat 

 production, 8183 > i' 1 m ^k secretion, 

 77-8 1, 91-93; in parthenogenetic re- 

 production, 177-180; in sugar produc- 

 tion, 86; in race, caused by external 

 influences, 290-293 ; in rate of cell 

 division, 340 ; in vital functions, 



