INDEX 



833 



Pelvic girdle. 147, 149, 150, 152, 672 



bird, 739 



python, 721 

 Pelvic saddle, 739, 747 

 Penguins, king. 731 

 Penis, 340, 343 

 Pepsin, 185. 187 

 Peptidases. 192 

 Perching in birds, 742 

 Pericardial cavity. 694 

 Pericardium, 695, 698 

 Periosteum, 143, 145 

 Periostracum, 636 

 Peripatus. 573, 574, 622, 798 

 Periphmeta americana, 258 

 Perissodactyla, 763 

 Peristalsis. 165. 697 

 Peritoneum, 558, 561, 694, 695, 709 

 Periwinkles, 75 

 Permeability, 22 

 Petals, 54, 64 



Petromvzon marinus, 666. 667 

 Phagocytes, 203, 205-207, 213, 536. 581 

 Phagocytosis. 606 



Phalanges. 144, 148, 150, 152, 693 

 Pharyngeal teeth. 673 

 Pharynx. 182, 206, 235, 236, 502, 507, 



539. 605 

 Phenotype, 393. 399 

 Philodina. 227 

 Phloem. 59-61. 63 

 Phonoreceptors. 317 

 Phoronid. 533 

 Phoronida. 551. 797 

 Phoronis. 550 

 Phosphatides. 199 

 Phosphocreatine, 164 

 Phosphorus, 174, 264, 266 

 Photoreceptors, 321, 325 

 Photosynthesis, 28, 51-61, 65, 77, 78, 83, 



426, 433 

 Phototropic. 325 

 Phrenic nerve. 238 

 Phrynosoma, 714, 718 

 Phylum, 795 

 Physalia, 467, 482, 483 

 Physeter macrocephalus, 767 

 Phytoflagellates. 432. 433. 437 

 Pia mater. 301. 302, 303 

 Pickerel. 80 

 Pigeons. 173, 741 

 Pika. 762, 799 

 Pilot snake, head. 716 

 Piltdown man. 772. 773 

 Pineal body. 256, 277, 304 

 Pineal stalk, 706 

 Pinfeathers, 731 

 Pinnixa chaetopterana, 554 

 Pinworms, 99. 524 

 Pipa pi pa, 682 

 Pisaster ochraceiis, 655 



Pistil, 54, 64. 65 



Pith. 59 



Pithecanlhropus erectus, 771, 772 



Pitocin. 273 



Pitressin. 252, 273, 274 



Pituitary gland, 250, 252, 256, 257, 260, 



265, 269, 270, 271-276, 304, 335, 



341, 343, 346-349, 350. 352. 705, 



706, 734 

 Placenta. 347, 348, 350, 378-382, 383, 



384, 385, 754, 758 

 Planaria, 178, 244, 499-507, 797 

 Plankton. 73, 74, 78, 84, 430. 433, 494, 



549, 632 

 Plant lice feeding, 599 

 Plants, 57, 59, 60 



Plasma, 196-202, 209-211. 249. 251, 253 

 PUismodiiim, 36, 429 



falciparum, 445, 447, 448 

 malariae, 445, 447 

 ovule, 445 



vivax, 99. 445, 446, 447 

 Plasmosome. 33 

 Plastid, 33, 53 

 Plastron, 724, 725 

 Platelets, 201, 207, 208, 211, 212 

 Platyhelminthes, 498, 663, 797 

 Plecoptera, 593 

 Pleodorina, 433 

 Pleucrobrachia, 493, 494 

 Pleura, 239 

 Pleural cavity, 695 

 Pleuroperitoneal cavity, 694, 695 

 Plexus. 295 



Plumatella, 544, 545, 547 

 Pneumothorax, 239 

 Podophyra fixa, 453 

 Polar body. 45-47 

 Poliomyelitis, 281 

 Polistes. 312 

 Pollen. 54, 64 

 Pollen basket. 615, 616 

 Pollen brush. 615, 616 

 Pollination, 2, 312. 616 

 Polychaeta, 565-567, 798 

 Polyclad, 509 

 Polycladida, 507 

 Polycythemia. 204 

 Polygordius, 534, 571 

 Polyneuritis, 173 

 Polyp, 465 

 Polyploidy, 412 



in salamanders. 414 

 in tomato plants, 413 

 Pond. 3. 4, 75 

 Population of animals. 67 

 Porifera. 454-464, 797 

 Porpoises, 764 

 Portuguese man-of-war, 466, 467, 468. 



474. 482. 483 

 Potassium, 174, 197, 199, 200, 267 



