INDEX 



869 



Plesiosaurs, 456 



Plethodon, 449, 840 



Pleura, 308, 532 



Pleural cavity, 532 



Pleurobrachia, 200, 832 



Pleuroperitoneal cavity, 403 



Pliny, 8 



Pliocene epoch, 725 



Podocopa, 836 



Poikilothermic, 448, 761 



Point mutation, 685 



Poison, 460, 462 



Poison claws, 305 



Poison glands, 322, 396. 506, 517 



Poison sac, 318 



Polar body, 122 



Polarity, 211 



Poliomyelitis, 543 



Pollen brushes. 317 



Polocyte, 1 22 



Polychaeta. 268. 834 



Polycladida, 213, 833 



Polyneuritis. 5 



Polyodon, 839 



Polyp. 188, 190 



Polyplacophora, 834 



Polypterus, 44U, 839 



Polyspermy, 124 



Pongidae. 741 



Pons. 600 



Population cycles, 773 



Population density, 770 



Population dispersal, 775 



Population genetics. 681, 691 



Population growth curve, 770 



Population pressure. 787 



Populations. 769 



ecologic characteristics of, 770 

 Porcupines. 500 

 Porifcra, 172-180, 236, 832 

 Porocytes, 1 74 

 Porpoises, 497 

 Portal veins, 620 

 Porto Santo rabbits. 695 

 Portuguese man-of-war, 191, 192 

 Posterior vena cava, 410, 549 

 Postganglionic fibers, 594 

 Postoral circle. 379 

 Potassium, 23 

 Potential energy, 47 

 Preadaptation. 447, 703 

 Preantennae, 324 

 Precocial. 483 



Predator-prey relationship, 766 

 Preformation theory. 133 

 Preganglionic fibers, 594 

 Pregnancy. 632, 633 



tests for, 633 

 Prehallux, 395 

 Premolars, 487, 516 



Preoral circle, 379 



Priapuloidea, 354, 835 



Price, Dorothy, 136 



Primates, 494, 842 



Primitive streak, 1 29, 640 



Primordial germ cells, 629 



Pristis, 434, 437, 839 



Probability, laws of, 655 



Proboscidea, 499, 842 



Proboscis, 220, 233, 248, 360 



Proboscis pore, 362, 381 



Proboscis worms, 232 



Procellariiformes, 841 



Procercoid larva. 218 



Proconsul, 741 



Producer organisms. 754 



Progeny selection, 656 



Progesterone, 619, 628, 632 



Proglottids, 216 



Prolactin, 626 



Pronephros, 561, 732 



Prophase, 41 



Propliopithecus, 741 



Proprioceptors, 107 



Prosobranchia. 251. 834 



Prosopyle, 174 



Prostate glands, 123, 570 



Prostomium, 267 



Protamine zinc insulin, 616 



Protection, 95 



Protective coloration, 785 



Protein. 27 



Proteose, 519 



Proterozoic era, 721 



Prothoracic glands, 330 



Prothoracicotropic hormone, 330 



Prothorax, 308 



Prothrombin, 541 



Protocooperation, 764 



Protobranchiata, 834 



Protonephridia, 208, 239, 286, 353. 388 



Protoplasm. 13, 16-33 



chemical composition of, 19 



dynamic state of, 74 



physical characteristics of, 30 

 Protopodite, 294 

 Protopterus, 439, 840 

 Protostomous animals, 381 

 Prototheria, 491, 842 

 Prototroch, 286 

 Protozoa. 33, 148-171, 832 



reproduction of, 166 

 Protraction, 402 

 Protura, 837 

 Proventriculus, 476 

 Proximal convoluted tubule, 562 

 Pseudemys, 456, 840 

 Pseudocoelom, 220, 229, 355 

 Pseudopod, 79, 99 

 Pseudoscorpiones, 835 



