INDEX 



547 



Rotifers, induction effect of 

 alcohol, 358 



Salamanders, effects of colored 



soil on, 358 

 Saleeby, 511 

 Savagery, 372, 408 

 Scholars, prize, 431 

 Schultze, double frog embryos, 



324 

 Science, duty of, 496 

 Segregation, apparent lack of, 

 289-293 

 fundamental to Mendelism, 



286 

 of Mendelian factors, 241, 



257 

 of substances in cells, 189 

 Selective Breeding, only meth- 

 od of improving race, 

 416 

 Spartan method, 417 

 Selection, value in Evolution, 



384 

 Self-control, 489, 491, 493, 494 

 "Self differentiation," 341 

 Self discovery, 489, 491 

 Semon, "Mneme" theory, 356 

 Sensitive periods, 318 

 Sensitivity, 51 

 differential, 52 

 general, 54 

 of germ cells, 53 

 Sex, a Mendelian character, 244 

 274, 276 

 influence of food and tem- 

 perature, 311 

 Sex cells, fundamentaly alike, 



13 

 Sex determination, 145-157 

 in human embryo, 145 

 in man, 151, 152, 153 

 McClung on, 147 

 Wilson on, 147 

 Stevens on, 147 



Sex glands, effects on develop- 

 ment, 337-339 

 Sex-limited inheritance, 215, 



274, 280 

 Sex-linked inheritance, 215, 



277-285, 304 

 Sex ratio, modification of, 146, 



154-157 

 Sexual reproduction, value of, 



163, 432 

 Shaw, Bernard, 454 

 Sheep, cleavage of egg, 29 

 Shull, leaf colors, 295 



heterozygosis, 396 

 Significance of cleavage, 128, 



190 

 of mitosis, 129-132 

 Simplex character, 255 

 Skin color, 203, 288-291 

 mulatto, 288, 297, 433 

 influence of light on, 311 

 Slow breeding of man, 299, 455 

 Sobotta, fertilization of mouse, 



120 

 Social inheritance vs. germinal, 



369-372 

 Social institutions, deal only 



with environment, 369 

 Society, highest grade of or- 

 ganization, 498 

 power of, 423 

 responsibility of, 498 

 supreme duty of, 504-507 

 Soil, poor, induction effect on 



plants, 357 

 Somatic discontinuity, 98 

 Somatoplasm, in cell body, 131 

 Somites, 25 



Sparta, destruction of unfit, 417 

 Special senses, origin of, 54 

 Specialized types, 430, 431 

 Specificity of Germ Cells, 158- 



168 

 Spencer, physiological units, 



106 



