INDEX 



Painted tortoise, 567 



Palaeognathae, 578, 579 



Palaeomaslodon, 629 



Paleontology, 8, 631 



Paleozoic Era, and rise of birds, 574 



Pallid bat, 584 



Pan, 587 



Pancreas, 47, 48, 49, 61. 72, 95, 117, 120, 



154; acinar cells of, 117; alpha cells of, 



120; beta cells of, 120; islet cells of, 120 

 Pancreatic duct, 50, 72 

 Pancreatic juice, 72, 117 

 Pandonna, 265, 267 

 Pantothenic acid, 33 

 Panu/ims, 440 



Paper chromatography, 200 

 Paper nautilus, see Argonauta 

 Papulae, of starfish, 489 

 Para-aminobenzoic acid, 33 

 Paracasein, 71 

 Paragonimus, 332 

 Paramecium, 248-257; as prey of Didimum, 



613; coordination in, 522; P. aurelia, 248, 



256; P. caudatum, 248, 256; P. multimicro- 



micleatum, 250; reproductive potential, 610 

 Paramylum, 241 

 Parapodia, 516; of Chaetoplerus, 401; of Nereis, 



397, 398, 402 

 Parascans eqtiomm, amphimixis in, 142; blas- 



tula of, 134; cleavage in, 142; meiosis in, 



138 

 Parasites, 607; anaerobic respiration in, 517 

 Parasitic flatworms, adaptations to parasitism, 



532 

 Parasitism, defined, 291; in branchiobdellid 



worms, 417; in development of pelecypods, 



377; in Hymenoptera, 469, 470; in leeches, 



417; in ticks and mites, 482 

 Parasympathetic nerves, 90, 115 

 Paratenodera, 461 

 Parathyroid glands, 95, 119 

 Parazoa, 219, 221, 222, 225 

 Parthenogenesis, 141, 534; artificial, 143; 



facultative, 535; in cladocerans, 535; in 



planarians, 322; in rotifers, 346-348 

 Partial metamorphosis, of aquatic insects, 455 

 Partial pressure, 80 

 Parturition, 1 18 

 Pasteur, and biogenesis, 260 

 Pathology, of Entamoeba histolytica, 237 

 Paurometabolous development, 454; in He- 



miptera, 462; in insects, 455; in Orthoptera, 



462; in termites, 459 

 Pavlov, 100 

 Pearl, Raymond, 174 

 Pearls, formation of, 379 

 Pearly nautilus, see Nautilus 

 Pearson, Karl, 174 

 Peas, inheritance in, 176, 177 

 Pecten, 374, 375, 379 



Pectinaria, 401, 402 



Pectinatella, 361 



Pectoral girdle, 93 



Pedal laceration, 306 



Pedicellariae, of Arbacia, 499; of starfish, 490 



Pedicellina, 357; protonephridia of, 520 



Pedipalps, 480; of scorpion, 482 



Pedogenesis, 141 



Pelecypoda, 216, 369, 370-381; circulatory 



system, 514; gas exchange, 516; nephridia, 



519 

 Pellagra, 33 



Pellicle, of Euglena, 239; of Paramecium, 250 

 Pelmatohydra, 285, 286, 300 

 Pelmatozoa, 216, 486 

 Pelomyxa, 236 

 Pelvic girdle, 93 

 Pen, of squid, 391, 528 

 Penguin, 576, 578, 579 

 Pcnial setae, of nematodes, 350, 351 

 Pentacrinoid larva, 507 

 Pentose sugar, see Simple sugars 

 Pentoses, 26, 27 

 Pepsin, 27, 71 

 Pepsinogen, 71 

 Peptidase, 72 

 Peptide linkage, 27, 71 

 Peptones, 71, 72 

 Peranema, 242 

 Perch, 559 



Perciopod, of crayfish, 428; of lobster, 427 

 Pericardial cavity, of crayfish, 431; of pele- 

 cypods, 374; of vertebrates, 48 

 Pericardial sinus, of crayfish, 429, 432, 



515 

 Period of division, 136, 138 

 Periostracum, 377, 528 

 Peripatus, 483 



Perisarc, 528; of Obelia, 301, 302 

 Perissodactyla, 580, 588 

 Peristalsis, 71 



Peristomium, of Nereis, 398 

 Peritoneal cavity, 49, 129 

 Peritoneum, 48, 57, 59, 69; of earthworm, 



414, 415 

 Peritrichida, 258 

 Perivitelline space, 144 

 Permeability, 99, 112, 113, 121, 124 

 Permian Period, and decline of amphibians, 



562; and diversification of reptiles, 566 

 Pernicious anemia, 34 

 Perophora, 550 

 Petromyzon, 555 

 Phalanger, 579, 609 

 Pharyngeal pouches, 55, 155 

 Pharynx, 48, 55, 60, 155; of digenetic trem- 



atodes, 330; of Melridmm, 307; of planarians, 



317 

 Phascolarclos, 582 

 Phenanthrene ring system, 26 



699 



