Index 



375 



ORIGIN OF SEX CELLS, 148 



DIVISION PERIOD, 148 



Primitive sex cells, 148 

 Oogonia, 148 



Spermatogonia, 148 



GROWTH PERIOD, 148 



Oocytes, 148 



Spermatocytes, 148 



MATURATION PERIOD, 153 

 ORTHOGENESIS, 215 

 OSBORN, Cartwright Lectures, 287 

 Otosclerosis, 69, 118 

 Ovaries, transplanted, 241, 242 



OviPARITY, 26 



Oviparous development, 13 

 Ovules, 10 



Oxychromatin, differential distribu- 

 tion, 206 

 in cell body, 204 



PAINTER, number of chromosomes in 



man, 163, 164 



"Pangenes" of deVries, 129, 205 

 Pangenesis, hypothesis of, 164, 237 

 Panmerism, 128 

 PARAMECITJM, avoiding reaction, 48 



behavior of, 46 



reactions to heat and cold, 40 



races differing in size, 67 



races of, 66 



rapid breeding of, 116 



selection in, 269 



trial and error, 47 

 Parthenogenesis, 134 

 "Particulate" inheritance, 73 

 Partition walls between cells, 206 

 PASTEUR, 335 

 PATHOLOGICAL CHARACTERS INHERITED, 



69 



PEARL, action of selection, 267 

 PEARL AND PARSHLEY, modification of 



sex ratio, 166 

 PEARSON, law of reversion, 77 



inheritance of tuberculosis, 69 



statistics, fault of, 81 

 Peas, Mendel's experiments on, 83 



monohybrids, 91, 92 



dihybrids, 92, 93 



trihybrids, 95, 96 



Permutations in distribution of chro- 

 mosomes, 173, 175 



Personality, determined by heredity, 

 321, 324, 327 



development of, 5, 56, 326 



infinity of chances in, 307 



not predetermined, 328 



potential, 334 



prediction impossible, 307 

 PHENOMENA OF DEVELOPMENT, 5 

 Phenotype, 93, 95, 96, 97, 273 



vs. genotype, 127 



Phototropism of Seedling, 41, 42 

 PHYLLOXERA, degeneration, of male- 

 producing spermatozoa, 167 

 Physiological characters, inheritance 

 of, 69 



division of labor, 31 



processes, 8-10 



states, 50, 330 



tests, 32, 173 



units, 129 

 Pigeons, behavior of, 51, 52 



numerous races, 260, 261 

 PITHECANTHROPUS ERECTUS, skull, 289 

 Pituitary gland influence on develop- 

 ment, 234 



"Plasomes" of Wiesner, 129 

 Plasticity of behavior, 51, 52 

 "Plastidules" of Elsberg and Haec- 



kel, 129 



Plastosomes, equal division of, 206 

 PLATE, ancestors of German Emper- 

 or, 78 



factors for coat colors of mice, 

 102 



Mendelian inheritance in man, 



114-121 



PLATO, on transmigration, 33 

 Polar bodies, n, 157 

 Polarity, 197, 198 



of Styela egg, 140, 141, 143 

 Polydactylism, 69, 116 

 Polyhybrid, 92 

 Population, normally stationary, 309 



of Europe, 310 

 Poultry, selection for egg production, 



267, 268 



PREFORMATION, 57, 177, 283, 323 

 "Preinduction," in Daphnia, 246 

 "Preinheritance," 113, 203 

 Prepotency, 82 



PRESENCE AND ABSENCE HYPOTHESIS, 

 97 



