530 



INDEX 



Rana, grafted tadpoles of, 341, 



Reactions, of germ cells, 43, 49 



machine-like, 465 

 Reason, 59-66 

 Reception cone, 109, 110 

 Recessive characters, 228 



"extracted," 230 



ratio to dominant, 233 

 Reduction of chromosomes, 136 

 Reflexes, 52-56 , 

 Regeneration, in eggs and 



adults, 318, 321 

 Reproduction, 12, 36 

 Responses, varied, 68 

 Responsibility, 443, 445, 459 



definition of, 467 



of society, 469, 470, 482 



varied, 468, 469 

 Retinal degeneration, 295 

 Retzius, human spermatozoa, 



11, 14 

 Reversible changes not in- 

 herited, 350 

 Reversion, 209, 223 

 Rickets, not inherited, 338, 340 

 Rigidity of behavior, 71 

 RiGNAN-o, "Centro - epigenesis" 



theory, 347, 495 

 Romanes, 369, 370, 495 



cattle, 374 



fowls, 371, S7S 



swme, 373 

 Rome, decay of, 485, 486 

 RosANOFF, insanity inherited, 



206, 500 

 Rotifers, induction effect of 



alcohol, 349 



Salamanders, effects of colored 



soil on, 350 

 Saleebx", 495 

 Savagery, 363, 396, 411 

 Scholars, prize, 415 

 Schultze, double frog embryos, 



316 

 Science, duty of, 480 



Segregation, apparent lack of, 

 280-287 

 fundamental to Mendelism, 



279 

 of Mendelian factors, 234, 



235, 251 

 of substances in cells, 183 

 Selective Breeding, only meth- 

 od of improving race, 

 404, 405 

 Spartan method, 404 

 Self-control, 471, 475, 477, 478 

 "Self differentiation," 332, 333 

 Self discovery, 471, 475 

 Semon, "Mneme" theory, 347, 



348, 495 

 Sensitive periods, 310 

 Sensitivity, 48 



differential, 48, 52 

 general, 52 

 of germ cells, 49 

 Sex, a Mendelian character, 238, 

 268, S69 

 influence of food and tem- 

 perature, 303 

 Sex cells, fundamentally alike, 



13 

 Sex determination, 138-150 

 in human embryo, 139 

 in man, 145, I46, 147 

 McClung on, 141 

 Wilson on, 141 

 Stevens on, 141 

 Sex glands, effects on develop- 

 ment, 329-331 

 Sex-limited ' inheritance, 209, 



268, 270, 274 

 Sex-linked inheritance, 209, 



270-278, 296 

 Sex ratio, modification of, 140, 



148-150 

 Sexual reproduction, value of, 



157, 416 

 Shaw, Bernard, 437 

 Sheep, cleavage of egg, SS 

 Shull, heterozygosis, 384 

 500 



