608 



INDEX 



Pleasure, 473, 474 



Plestiodon septentrionalis, head, 383 



Pleural cavity, 408 



Pleurobrachia bachei, 154 



Pliny, 550 



Ploughshare bone, 390 



Plover, and crocodile, 495 



golden, 403 

 Plumage, 401 

 Plumatdla, 188, 189 

 Plumatella repens, 188 

 Pneuma, 562, 653 

 Pocket mice, 417 

 Podophrya, 84 



Poikilothermous animals, 466 

 Poison claws, 2G9, 300 

 Poison glands, 297, 387 

 Polar bear, 509 



Polar bodies, 109, 110, 112, 113, 418 

 Polarity, 117, 238, 468 

 Poles, egg cell, 118, 371 

 Polian vesicles, 194, 196, 205 

 Polistotrema stouti, 335 

 Pollen, 292 

 Polyandry, 403, 493 

 Polyaxon spicules, 130, 131 

 Polycelis, 166 

 Polychaeta, 243 

 Polygamy, 403, 493 

 PolygordiuK, 241, 242 



Polymorphism, 147, 148, 160, 292-295, 431, 543 

 Polyps, 142-148, 150, 151 

 Polypterus, 344 

 Polypterus senegalus, 345 

 Polypus himaculatus, 223 

 Pond communities, 479 

 Porcupines, 414 

 Porifera, 127, 545, 546, 547 



(See also Sponges) 

 PoTospora, 84 

 Porpoises, 417 

 Portal systems, 340 

 Portal vein, 409 



Portuguese man-of-war, 143, 148, 431 

 Position, organs of, 445 

 Positive response, 55 

 Postembryonic development, 460 

 Posterior chamber, eye, 332, 333 

 Potassium, 18 

 Potato beetle, 285 



Potential energy, 14, 37, 430, 452, 463 

 Potential immortality, 452 

 Prairie chicken, 509 

 Prairie dogs, 507 

 Precaval vein, 339 

 Precocial young, 404 

 Predatism, 498 



Preformation theory, 662, 554 

 Pressure sensations, 446 

 Priapulus caudatus, 247 

 Primates, 411, 415 

 Primordial germ cells, 107-110, 447 

 Priority, 59, 646 

 Prismatic layer, 210 

 Proboscidea, 417 



Proboscis, 157, 158, 182, 183, 273, 623, 524, 544 



Procoracoid, 388 



Proctodeum, 371, 372, 438 



Proglottid, 165, 166, 168 



Pronephric duct, 317, 325, 326 



Pronephric tubules, 325, 326 



Pronephros, 325, 326, 336, 442 



Pronghorn, 609 



Pronotum, 271 



Pronuclei, 112, 113 



Prophase, 47, 48 



Proprioceptors, 445 



Propterygium, 361 



Prosoma, 299, 300 



Prostate gland, 160, 161, 182 



Prostomium, 229, 230, 232, 242, 243 



Protective epithelium, 90 



Protective resemblance, 485, 486 



Proteins, 19, 34, 38, 464 



Proterospongia, 80, 127 



Proterospongia haeckeli, 80 



Proterozoic era, 511, 512, 513 



Prothorax, 271, 272 



Protista, 40 



Protocercal tail, 349 



Protonephridium, 241, 242 



Protons, 8 



Protoplasm, 16, 18-23, 28, 40, 84, 429, 618 



Protopterus, tail, 349 



Protopterus annectens, 347 



Prototheria, 410 



Protozoa, 78, 646, 647 



Protozoaea, 265, 266 



Protozoans (in general), 40, 63-90, 433-443, 400, 



461, 460, 467, 469, 480, 487, 488, 494, 490, 



497, 513, 552 

 Protozoology, 6 

 Protracheata, 305 

 Protylopus, 525 

 Proventriculus, 230, 277, 393 

 Psalterium, 416 

 Pseudopodia, 63-66, 78 

 Pseudopodiospores, 68 

 Pseudoscorpions, 302, 303 

 Psychology, 5 

 Pterodactyls, 397, 515 

 Pterygium, 361 

 Pterygoid, 386 



Ptilosarcus quadrangularis, 147 

 Ptyalin, 321 

 Pubis, 321, 388 



Pulmonary artery, 360, 361, 379, 409 

 Pulmonary chamber, 219 

 Pulmonary vein, 409 

 Pulp cavity, 407, 408 

 Pulsating vacuoles, 64 

 Pulvillus, 274 



Pupa, 279, 281, 280-289, 292 

 Pupil, eye, 332, 333 

 Purkinje, 18 

 Pus cells, 490 

 Pygostyle, 390 

 Pyloric caeca, 193, 195, 360 

 Pyloric opening, 322 

 Pyloric sac, 195 



