542 



INDEX- 



OX, 453 



Oxidation, 17, 68 

 Oysters, 242, 256, 259 



Palamonetes, 295 



Palaeontology, 479 



Palseozoology, defined, 5 



Paludicolae, 417 



Papilio, 305 



Parapodia, 236 



Paramecium, 149, 153 



Parasitic worms, 206 



Parasitic worms, cycle of, 206 



Parasitism, 129, 195, 204, 206 



Parental care, 115, 460 



Parthenogenesis, 114 



Passeres, 429 



Pea-fowl, 421 



Pearls, 257 



Pearl oyster, 259 



Pecten, 259 



Pelagic fauna, 135 



Pelecanus, 416 



Pelecypoda, 257 



Penguin, 413 

 Pennaria, 185 



Perennibranchiata, 383 



Pericardial sinus, 283 



Perichondrium, 55 



Periosteum, 56 



Peripatus, 296 



Peripheral nervous system, 79; 347, 



351 (see nervous system). 

 Perissodactyla, 453 

 Peritoneum, 316 

 Periwinkles, 260 

 Perodipus, 455 

 Petrels, 414 

 Pharyngognathi, 373 

 Pharynx, 333 

 Pheasant, 421 

 Philosophy of biology, 515 

 Phasnicopterus, 415 

 Pholas, 258 

 Phyla, key to, 147 

 Physalia, 187 



Physiology, defined, 4; history of, 513 

 Physopoda, 299 

 Physostomi, 372 



Pici, 426 



Pieris, 303 



Pigeon, 417 



Pigments, n 



Pituitary body, 341 



Placenta, 448 



Placentalia, 439, 450 



Planarians, 193 



PlanorbiS, 261 



Plant-lice, 299 



Planula, 184 



Plasma (blood), 57, 338 



Plastron, 392 



Platyhelminth.es, 192 



Plecoptera, 298 



Plectognathi, 373 



Pleura, 337 f 



Pleuron, 266 



Plexus, 352 



Plover, 417, 433 



Plumatella, 192, 202 



Polar bodies, 33, 34, 35 



Polychaeta, 236 



Polygordius, 234 



Polymorphism, 119, 188, 189 



Polyp, 175-178 



Polyzoa, 202 



Porcupine, 456 



Porifera, 147, 164 



Porpoises, 452 



Potato-beetle, 304 



Prairie dog, 457 



Premolar (teeth), 443 



Primary vesicles (brain), 347 



Primates, 451, 458 



Primordial germ cells, 32, 33, 34 



Proboscidea, 454 



Procotodoeum, 67, 280 



Proglottis (segment), 198, 199 



Promorphology defined, 3, 91; illus- 

 trated, 91 



Prophase, 24 



Prostomium, 229 



Protective resemblance, 125 



Proteids, n 



Prothorax, 272 



Protoplasm, 10; chemical composition 

 of, 1 1 ; physical structure, 1 1 ; physi- 

 ology, 12, 65; relation to life, 9 



