7 i6 



INDEX 



Biophors, 14, 208. 



Biparental inheritance, 529-533. 



Birds, effect of heat upon development 

 of, 259 ; variation in digits of, 56. 



Birthmarks, 189-191. 



Bisexual reproduction, a cause of varia- 

 tion, 160-163; introduces no new 

 characters, 163. 



Blackberry, evolution of, 131-133. 



Blemishes on breeders, 590. 



Blend in characters, 481. 



Blended and exclusive inheritance, 475. 



Bonnet, experiments in regeneration, 

 316. 



Bonnier, experiments on acclimatiza- 

 tion, 378; experiments with dande- 

 lion, 223. 



Born, experiments in grafting, 108, 336. 



Brain not necessary to coordinated 

 motion, 400, 401. 



Breeder's business is the production of 

 sires, 605. 



Breeders' fads, 594. 



Breeders of speed and breeders of 

 breeders contrasted, 557. 



Breeding, polymorphism in, 476, 477 ; 

 problems of, outlined, 3-5 ; purposes 

 in, 599, 600 ; systems of, 599-627 ; 

 true, or stability of type, 541-544. 



Brown-Sequard, experiments on mutila- 

 tions, 367. 



Bruce, studies in mammae, 47. 



Bud variation, 181. 



Bud varieties reproduce by seeds, 181. 



Bull, E. W., originator of Concord 

 grape, 134. 



Bullfinch, effect of food upon, 228. 



Bumblebee, antenna of, developed as a 

 foot, 43. 



Burbank system of planting, 643. 



Burrill, experiments in crossing straw- 

 berries, 184. 



Camel, development of foot of, 60. 



Castration, indirect effects of, upon the 

 body functions, 100. 



Catalytic poisons, 266. 



Cats, variation in digits of, 57. 



Cattle, acclimatization of, 375 ; develop- 

 ment of foot of, 58 ; meristic variation 

 in digits of, 62, 63 ; reversions in, 192. 



Cave animals, 242. 



Cell, the, as a structural unit, 143, 144; 

 differentiation in, 144 ; effect of grav- 

 ity upon, 239. 



Cell division, as a cause of variation, 

 155-181; irregularities in, 150-152; 

 mechanism of, 145-152; outline of, 



146, 147; variation in rate of, 340; 

 with and without differentiation, 149- 

 150. 



Centgener plots, 644. 



Centrosome, 146. 



Cervical fistulas in mammals, 44. 



Chance, accounts for unusual occur- 

 .rences, 187; as distinct from cause, 

 365 ; law of, 365, 366. 



Character, defined, 17; meaning of 

 term, 11-13. 



Characters, acquired, 182 ; acquired from 

 the environment, 302-304, 308-311; 

 acquired, inheritance of, 349 ; are not 

 "acquired," 358-360; blended, 481; 

 combine in definite proportions, 504- 

 513; congenital and acquired, 354- 

 356; dependent upon sex, 194-196; 

 development of, how influenced, 361- 

 363; dominant and latent, 13, 14; 

 dominant and recessive, 514, 515; 

 elementary, 14; how behave in trans- 

 mission, 473-478 ; latent, 474 ; not 

 necessarily adaptive, 412; of adult 

 as influenced by development, 350; 

 of the individual are those of the 

 race, 357; origin of, 413-415; origin 

 and degeneracy of, contrasted, 415; 

 too many, in animal breeding, 656, 

 657; variability of, in same popula- 

 tion, 444. 



Chemical action, acclimatization to, 308- 

 311 ; of secretions, 383, 384. 



Chemical effects of light, 240. 



Chemical reactions of protoplasm, 264- 

 285. 



Chemicals, effect of, upon germination, 

 271 ; rhythmical contraction stimu- 

 lated by, 276-278. 



Chemotaxis, 271, 272. 



Chemotropism, 271-276. 



Chromatin granules, 145. 



Chromatin matter, 145-152. 



Chromomeres, 146. 



Chromosomes, 146-152; but half the 

 normal number of, in parthenogenetic 

 individuals, 180; composition of, 

 1 74 ; constant in number for the 

 species, 146; number of, even in 

 bisexual reproduction, 146; number 

 of, reduced by maturation, restored 

 by fertilization, 170; number of, 

 sometimes halved, 180. 



Chrysanthemums, experiments with, by 

 De Vries, 119-121. 



Cleavage, effect of outside conditions 

 upon, 340 ; geometrical character of, 

 339- 



