472 



Pavlov, Ivan (1849- ), 326, 327 



Pearl, Raymond (1879- ), 343 



Pearson, Karl (1857— ), 348 



Perfecting principle, 377, 401 



Perfection, 442 



Persistence of primitive types, 190 



Pfeffer, Georg (1852- ),4-27 



Phagocytosis, 457 



Phenotype, 179, 181, 191, 241, 370 



Phylogeny, 140 



Pigeon, dy 



Pigmentation, 220, 221, 222 



Piltdown skull, 18, 198 



Pineal gland, 102 



Vithecantropus erectus, 18, 197, 198 



Pituitary gland, 102, 214 



Polyploidy, 387, 389 



Polytheism, 433 



Population, poessure of, 192, 331, 336, 



339 

 Potato beetle, 163 

 Prediction as test of theory, 48 

 Precipitin tests, 1 14 

 Preformation, 122, 123 

 Prenatal influence, 301, 318 

 Primate skulls, 201 

 Primates, 194, 203, 204 

 Probability, law of, 160 

 Propagation, vegetative, 176 

 Propliopithecus, 202 

 Protective, characters, 149; coloration, 



150, 342, 343; resemblance, 274, 343, 



344. 347, 362 

 Public Health, 458 

 Punnett, Reginald C. (1875- )> ^4^, 



335 

 Pure lines, 178, 349 



Purpose, 424; in explanations, 410; in 

 nature, 455; of man as purpose in 

 nature, 456 



Purposefulness of life activity, 456 



Quetelet, Lambert Adolphe Jacques (1796— 

 1874), 160 



Races of man, 208, 210 



Racial poisoning, 395 



Radium, 164, 323; action on germ cells, 



164 

 Rationalization in morals, 461 

 Rationalizing, 449 

 Recapitulation, 133, 142 

 Recessive, 211, 232, 235, 241, 242, 24J 



Index 



Recombination, 242, 256, 266; of factors, 



396 

 Reduced organs, 103 

 Reduction division, 2J3, 256, 258 

 Regeneration, 315 

 Regression, law of filial, 351 

 Religion, and science, 281, 296; evolution 



and, 294 

 Reproduction, 63 

 Resemblances, degrees of, 69 

 Responsiveness of organisms, 307 

 Reversion, 103, 178, 248 

 Rhodesian man, 198 

 Rickets, 221 



Romanes, George John (i 848-1 894), iii 

 Rousseau, Jean Jacques (17 12— 1788), 



302 

 Rudimentary structures, 134 

 Rust in wheat, 361 

 Rontgen, "Wilhelm Conrad (1845-1923), 



416 



Saber-tooth tiger, 34 



Sacculina, 108, 140 



Saint-Augustine (3J4— 430), xi, xii, xiii, 



295, 410 

 Saint-Hilaire, Geoflfroy (1772-1844), 282, 



284, 303 

 Saltation, 380 

 Schmankewitsch, Alexander (1850— ), 



171 

 Schultz, Adolph H. (1891- ), 208 



Science, and dogmatism, 300; and religion, 



299 

 Scientific method, 412, 446 

 Sea-squirt, 3 5 



Secondary sexual characters, 364, 366 

 Sedimentation, 22, 25 

 Seed-plant, 38 



Segmentation of egg, 125, 128 

 Segregation, 238, 239, 241, 242, 255, 261, 



274, 323, 382; and germ cells, 245; 



Mendel's explanation of, 247 

 Selection, and heredity, 356; efiFects of, 180, 



350; limits of, 356; measuring, 348; 



natural and artificial, 178, 336 

 Semon, Richard (1859-1919), 309 

 Serum, sensitized, 113, 118 

 Serum therapy, 457 

 Sex, chromosome, 257; determination, 256, 



258, 259, 260 

 Sex-linked, characters, 261, 264; inherit- 

 ance, 262, 263; recessive, 319 



