434 



INDEX 



Plate on heredity, 225 

 Platodes, 263, 279 

 ^Plavj analysis of, 60-77 

 "7, animal, 60-77 

 Plural variations, 259 

 Plesiosaurus, the, 120 

 Plectognathic fishes, 177 

 Poisoning of germs, 223 

 Poisonous butterflies, 148 



,, organisms, colours of, 147 

 snakes, 139, 143 

 Polar animals, colour of, 54-5 

 Political systems, development of, 



413 



Pollen, 197 

 Polyp, the, 284, 291 

 Pond, inhabitants of the, 2 1 

 Pond-mussel, the, 175 

 Pond-snail, the, 239 

 Porto Santo rabbit, the, 34 

 Potential imrnortality, 307 

 Presentiment of the bird, 107 

 Preyer on the nature of life, 315 

 Proboscis of butterfly, 201-2 

 Processional butterfly, 43 

 Proper names, 393 

 Protective colours of insects, 189 

 Protoplasm, 289 

 Protozoa, the, 170, 263, 292 

 Psychic phenomena, 384 



in inorganic 



matter, 404 

 Psychic phenomena in the protists, 



43 



Psychology, 384 

 Pterodactyl, the, 121 

 Pterosauri, the, 120, 130 

 Pupa, the, 1 88, 206 

 Purpose in organisms, 354 

 in science, 373 



RACIAL colours, cause of, 165 

 Realky^ nature of, 395 



not given in natural science, 



383 

 Recreation not the essence of play, 



61 



Red breast in birds, 81, 82 

 Redstart, the, 45 

 Reduction cleavage, 321 

 Reflex action, 64,214 

 Regeneration of organs, 142 

 Regions of nature, 20 

 Regulation of rivers, 177 

 Reproduction, essence of, 294 



rate of, 58 



Reptiles, age of, 135 

 Rhine salmon, 48 



Rhodeus, the, 1 75 

 Richard's pipit, the, 109 

 Rigid types, 132 

 Ringed adder, the, 139, 148 

 Rivers, artificial control of, 48 

 Rock-pigeon, the, 30 

 Rudimentary organs, 158-70 



parts in germs, 295 



Ruffe, the, 178 

 Rut of animals, 57 



Sacculzna, 246 

 Salamander, the, 37 



and fire, 146 



Salmon, spawning of the, 180-1 

 Satyridae, the, 188 

 Scar in the egg, 304 

 Scars, use of, 144 

 Scented butterflies, 195 

 Schiller on play, 62 

 . -Srieiu e. iilj;<rruvily of, 391 

 Srit-niific explanation, nature of, 361 

 Scolices, 280-1 

 Sea-anemones, 285 

 Seed of plants, 198 

 Selective value, 329 

 Self-correction of determinants, 336 

 Self-deception in play and art, 71-2 

 ySelf-preservatJQn, instinct of, 356 

 S-.-nsations as psychic elements. ;.,.S.; 

 Sense-impressions, 65 

 Sense of life, 426-7 

 Senses, action of the, 391 

 Serpent, habits of the, 138 



movements of the, 140 

 Sexual characters, 82-5 



generation, nature of, 299 



selection, 80-3 



Ideological, 370 



union, reasons for, 256 

 Shad, the, 173 

 Shamming death, 193, 216 

 Shell of the snails, origin of the, 241 

 Silurian strata, animals in the, 121 

 Skeleton of the articulates, 203 

 Skull, development of the, 153 

 Smooth adder, the, 141 

 Snail, the, 239 



breathing of the, 244 

 Snails with small shells, 168 

 Snipe, noise of the, 96 

 Social instincts, culture of, 408 



,, instinct in birds, r 12 

 Society, growth of, 407 

 Sociology, 406 



laws of, 407 

 Species, nature of a, 33, 117 



persistence of, 132-3, 135 



