INDEX 



529 



Physiological division of labor, 10, 



58, 65, 232-234, 330, 336 

 Physiologus, 449 

 Physiology, 3, 4, 366-368, 389, 449, 



454, 459-464 

 Pig, 130, 398, 400, 401 

 Pigeon, 362, 376 

 Pigment, 11 

 Pile village, 442 

 Pill-bug, 90 



Piltdown man, 433, U3U, 438 

 Pine bark beetle, 412 

 Pineal body, 202-204 

 Pinna, 213 

 Pisces, See: Fishes 

 Pithecanthropus, U32, 433 

 Pituitary gland, 193, 198 

 Placenta, 128, 192, 193, 272, 273 

 Placental, 128-131, 321, 479 

 Plague, 402, 406, 407 

 Planaria, 78, 79, 396; See: Flatworm 

 Plant, 30-35, 37-45, 404, 408-412, 



417, 462, 463 

 Plantigrade, 321, 322 

 Plasma, 64, 166, 169 

 Plasma-membrane, 19 

 Plasmodium, 53, 3U0, 396, 477 

 Plastid, 19, 30, 32; See: Chloroplast 

 Plastron, 121 

 Plato, 447 



Platyhelminthes, 78, 79, 477, 480 

 Pleistocene epoch, 359, 363, 364, 368, 



432 

 Pleura, 163 

 Plexus, 205, 206 

 Pliny, 449 



Pliocene epoch, 359, 362 363, 368 

 Pliohippus, 362, 363 

 Ploidy, 310 

 Plum, 416 

 Plumatella, 83 

 Pneumonia, 391 

 Podura, 92 

 Point change, 311 

 Poison gland, 357 

 Polar lobe, 376 

 Pollen, 333, 334 

 Pollen basket, 331, 333, 334; brush, 



33J-333; comb, 331, 333 

 Pollination, 33U, 416 

 Polocyte, 243, 2U5-2U7, 252, 30U 

 Polychaeta, 81, 477 

 Polymorphism, 73, 234 



Polyp, 71-78, 98, 99 



Pond community, 335 



Population, 378-381 



Porcupine, 129 



Porifera, 67-71, 477, 480 



Pork, infected, 400, hOl 



Porpoise, 129, 323, 357 



Portal vein, 157, 158, 172, 173 



Porto Santo rabbit, 372 



Portuguese man-of-war, 73 



Position effect, 311 



Potato beetle, 9U, 409 



Potential energy, 14, 22, 507; See: 



Energy 

 Pottery, 442 

 Precipitin, 343, 367 

 Preformation, 274, 280, 453, 467, 470 

 Pregnancy, 191-/93, 273 

 Prehistoric man, 431-437 

 Prehuman lineage, 426-431 

 Pressure, 320; receptors, 210 

 Preventive medicine, 389 

 Priestley, 463 

 Primary, germ lavers, 61; tissues, 61, 



104 

 Primate, 128, 130, 131, 352, 426-431, 



480 

 Primordial germ cells, 238, 305; See: 



Germ cells 

 Probability, theory, 227 

 Proglottid, 398, 399 

 Pronephros, 133, 18h, 185, 270 

 Prophase, 240, 2U1 

 Prorodon, 5U 

 Prosopyle, 70 

 Prostate gland, lh8, 19U 

 Prostomium, 82 

 Protective mimicry, 328 

 Protein, 21-23, 33, 39, 151, 155-159, 



225 

 Proteose, 156 

 Proterozoic era, 359-361 

 Prothorax, 330, 331 

 Protococcus, 30-35 

 Protophyta, 35 

 Protoplasm, 3, 10, 14-29, 388, 464, 



465; appearance, 17; composition, 



20-23; concept, 15; organization, 



18-20, 254, 275-280; structure, 17 

 Protopodite, 106, 107 

 Prototheria, 479 

 Protozoa, 35-56, 209, 223, 229, 232, 



244-246, 248, 255-261, 284, 318, 



