INDEX 



545 



in Styela, Amphioxus, frog, 

 125 

 Organism of humanity, 505 

 Organization, 10 

 Organogeny, 31 

 Origin of Sex Cells, 132-144 



Division period, 134 



Primitive sex cells, 134 



Oogonia, 134 



Spermatogonia, 134 



Growth period, 135 



Oocytes, 135 



Spermatocytes, 135 



Maturation period, 141 

 Orthogenesis, 313 

 Osborn, Cartwright Lectures, 



408 

 Otosclerosis, 206, 304 

 Ovaries, transplanted, 351-355 

 Oviparity, 32 



Oviparous development, 18, 19, 

 Ovules, 13 



Oxychromatin, differential dis- 

 tribution, 191 



in cell body, 188 



"Pangenes" of deVries, 106 

 Pangenesis, hypothesis of, 98, 



343 

 Paramecium, avoiding reaction, 

 67 

 behavior of, 66 

 reactions to heat and cold, 



57 

 races differing in size, 



204 

 races of, 211 

 rapid breeding of, 299 

 selection in, 386 

 trial and error, 68 

 Parthenogenesis, 114 

 "Particulate" inheritance, 214 

 Partition walls between cells, 



191 

 Pasteur, 490 



Pathological characters in- 

 herited, 205-208 

 Pearl, action of selection, 387 

 Pearl and Parshley, modifica- 

 tion of sex ratio, 155 

 Pearson, ancestral inheritance, 

 222 

 inheritance of tuberculosis, 



207 

 statistics, fault of, 225 

 Permutations in distribution of 



chromosomes, 162 

 Personality, determined by her- 

 edity, 463, 469 

 development of, 7, 84, 472 

 infinity of chances in, 440, 



441 

 not predetermined, 469 

 potential, 490 

 prediction impossible, 440 

 Phenomena of Development, 6 

 Phenotype, 247, 249, 250, 392 



vs. genotype, 102 

 Phototropism of Seedling, 58 

 Phylloxera, degeneration, of 

 male-producing sperma- 

 tozoa, 156 

 Physiological characters, in- 

 heritance of, 208 

 division of labor, 40 

 processes, 10, 12 

 states, 73, 480 

 tests, 42, 160 

 units, 106 

 Pigeons, behavior of, 75, 76 

 numerous races, 376, 377* 

 378 

 Pineal gland, 170 

 Pithecanthropus erectus, skull 



409 

 "Plasomes" of Wiesner, 106 

 Plasticity of behavior, 76 

 "Plastidules" of Elsberg and 



Haeckel, 106 

 Plastosomes, equal division of, 

 190. 



