832 



INDEX 



Oligochaeta. 555-565, 798 



Omasum, 183, 184 



Ommatidia, 584 



Omnivorous animals, 172, 173 



Onychophora, 573, 622, 798 



Oogenesis, 43-45, 46 



Oogonium, 45, 46 



Ookinete, 447 



Operculum, 375, 644, 675 



Ophiuroidea, 652, 653, 798 



Opossum, 756, 760, 782 



Optic lobe, 705 



Optic nerve, 279, 326, 327-329. 373, 611, 



706 

 Optic vesicle, 373, 374 

 Orangutan, 770 

 Orb web, 626, 627 

 Order, 795 

 Organ, 107 



Organic compounds, 28 

 Organoids, 33, 35 

 Ornitholestes, 727 

 Orthoptera, 593 

 Osculum, 456, 459 

 Osmosis, 22, 23, 61, 63, 674 

 Osmotic pressure, 22, 26, 28 

 Ossicles, 655, 657, 658 

 Osteichthyes, 666, 668, 798 

 Ostracods, 587, 588 

 Ostrea ediilis, 6A1 



liirida, 633, 642 

 Ostrich, 70, 728, 729 

 Otolith, 316. 317 

 Outbreeding, 413 

 Outer ear, 317, 318, 320 

 Oval window, 320 

 Ovary, 333, 344, 345 



bird, 746 



frog, 709, 710, 711 



human, 256, 346, 349, 350, 352 



mammalian, 347, 351 



plant, 54, 64, 65 



whale, 348 

 Oviduct, 346 



bird, 746 



frog, 709, 711 

 Oviparous animals, 359, 716 

 Ovipositer, 604, 605, 617 

 Ovoviviparous animals. 716 

 Ovulation, 345, 350-353, 381, 709-711 

 Ovules, 64, 65 



Oxygen. 199. 224-227, 230, 236 

 Oxygen cycle, 77, 78 

 Oxyhemoglobin, 203, 236 

 Oyster, 630, 631, 633, 798 



Pacemaker. 217-220 

 Pacinian corpuscles, 310 



Palaemonetes exilpes, 257 

 Paleozoic era, 779 

 Paloio worm. 552 

 Palpi, 601, 602 



Pancreas, 189, 191, 216, 256, 267, 268, 

 697 



development of, 375 

 Pandeka. 668 

 Pandorina, 429 

 Paracelsus, 261 



Piiragoniinus westermani, 512 

 Paragordius, 530, 531 

 Paramecium, 27, 36, 280, 450 



appearance, 449 



behavior, 451 



excretion, 451 



general structures, 449 



nutrition. 451 



reproduction. 332-334, 451, 452 



respiration, 451 



support and movement, 449 

 Paramecium aitrelia, 333 



bursaria, 428 



caudatiim, 450, 452 

 Paranemertes peregrina, 535 

 Parasites, 93, 95-97, 425, 426, 429, 433. 

 436. 437. 498. 499. 508-532, 569. 

 598. 600. 626. 628. 641, 644 

 Parasympathetic nerves, 294 

 Parasympathetic system, 295, 297 

 Parathyroid glands, 140, 200, 256, 263, 



264, 266 

 Parchment worm, 568 

 Parotid, 180 

 Pars anterior, 260, 263, 267, 269, 270- 



276, 335, 341, 349, 350 

 Pars intermedia, 269, 270, 272, 276 

 Pars nervosa. 269. 270, 273-275 

 Pars tuberalis. 269, 270. 273 

 Parthenogenesis. 99. 339. 340, 412, 539, 



541, 542, 587, 591 

 Pasturellu tularemia, 629 

 Patella, 150, 152, 534 

 Pavlov, I., 188, 290 

 Peacock worm, 553 

 Pearl, formation of, 637 

 Pecten, 165, 640, 642 

 Pecten comb, 615, 616 

 Pectinatella magnifica, 544, 545 

 Pectoral girdle, 672 



bird, 739 



turtle, 725 

 Pedicellariae, 654, 655, 658 

 Pediculus human Is, 97 

 Pedipalps, 623 

 Pedogenesis, 340 

 Peking man, 772 



Pelecypoda, 631, 633, 634-642, 798 

 Pelmatohydra oligactis, 469 

 Pelomyxa palustris, 429, 438 

 Pelostoina flumineum, 103 



