INDEX 



715 



Nitrogen compounds, 520 



cycle, 511,633 



-fixing bacteria, 510 

 Noctiluca, 46, 49 

 Noctuidae, 264 

 Nocturnal birds, 453 

 Node of Ranvier, 353 

 Nomenclature, 9 

 Nomeus, 121 



Non-oxygenated blood, 340, 533 

 Northern pike, 388 

 Norway rat, 485 

 Nose, 547 

 Nosema, 5 3, 74 

 Nostrils, 566 

 Notochord, 315, 318, 319, 321, 



322, 324, 357, 565 

 Notonectidae, 263 

 Notopodium, 184, 186 

 Nuclear membrane, 21, 22 



sap, 22 

 Nucleolus, 21, 22 



neuron, 353 

 Nucleoplasm, 21, 22 

 Nucleus, 21, 108, 110, 138, 152, 

 179 



fusion, 115 

 Nudibranch, on cover of book, 



282, 293 

 Numida, 456 

 Nummulites, 77 

 Nut clam, 282 

 Nuthatches, 462 

 Nutrition, 512, 514-525 



crayfish, 204 



food, 509 



frog, 331 



Hydra, 112 



man, 514-525 



Paramecium, 57 



types, 512 



utilization, 541, 542 



vitamins, 521-525 

 Nutritive cell, 105, 107 

 Nutritive processes, 509 



absorption, 524 



carbon cycle, 510 



digestion, 513 



energy, 511 



food, 509 



nitrogen cycle, 511 



nitrogen-fixing bacteria, 510 



photosynthesis, 509 



types, 512 

 Nyctotherus, 66 

 Nymph, 239 

 Nymphalidae, 265 



O 



Obdia, 118,119,127 



life history, 118,119 

 Oblique muscle, 506 

 Obstetrical toad, 397 



Occipital. 345, 500, 502, 507 



condvlc, 344, 456 



lobe, 546 

 Occipitovertebral artery, 336, 338 

 Oceanic region, 632, 642 

 Ocellus, 230, 231,232, 233 

 Ocelot, 494 



Octopus, 293, 296, 297 

 Oculomotor nerve, 351, 353, 546 

 Odd-toed hoof, mammals, 487 

 Odobemis, 480 



Odonata, 229, 241, 250, 260, 263 

 Odontoceti, 496 

 Ocstridae, 265 

 Oil birds, 461 



gland, 434 

 Old-World lizard, 430 



monkey, 489 

 Olfactory bulb, 546 



hair, 225 



lobe, 350, 351 



nerve, 350, 351 



organs, 355 



pit, 231,320,477 



tract, 546 

 Oligocene period, 618 

 Oligochaeta, 171, 185, 189, 196 

 Omasum, 488 

 Ommatidium, 210, 231 

 Omnivorous animals, 485, 512 

 Omosternum, 345 

 Oniscus, 217 

 Ontogeny, 613 

 Onychophora, 218, 222 

 Oocyst, 69 

 Oocytes, 80, 238, 577 



primary, 80, 577 



secondary, 80, 577 

 Oogenesis, 80, 115,212, 563 

 Oogonia, 80, 238, 577 

 Ookinete, 68, 69 

 Ootype, 140, 144 

 Opalina, 64, 65 

 Operculum, frog, 358 



horseshoe crab, 274 



perch, 378 



polychaete, 186 

 Ophioderma, 313 

 Ophisaurus, 430 

 Ophiuroidca, 304, 313 

 Ophthalmic artery, 206, 336 

 Opisthobranchia,'282, 301 

 Opisthorchis, 145 

 Opossum, 464, 479 

 Optic, chiasma, 350, 351, 546 



cup, 566 



lobes, 350,351 



nerxe, 350, 351, 546, 550 



tract, 546 



ventricle, 351 

 Oral, 130 



arm, 122 



disk, 123 



funnel, 361, 362 



Oral (Cont.): 



groove, 55 



hood, 318 



lobe, 118, 120 



nerve ring, 306 



papillae, 224 



side, 56 



spear, 153 



sucker, 139, 140 

 Orang-utan, 489 

 Orb web, 272 

 Orbicularis oculi, 507 



oris, 507 

 Orbit, 436, 437 

 Orbitosphenoid, 466 

 Orb-weaving spider, 272 

 Orconectes, 221 

 Order, 8 



Ordovician period, 617 

 Organ, 86 



of Corti, 549 



of equilibrium, 288 



pipe coral, 128 



system levels, 133 

 Organic compounds, 17 



evolution, 610, 620 



-inorganic cycle, 633 

 Organism, 90 

 Organizer, 568 



theory, 568 

 Organogeny, 83, 84 

 Oriental rat flea, 262 



sore, 71, 262 

 Origm of life, 601-627 



Metazoa, 91 



muscle, 346, 350 



parasirism, 641 



species, 609, 617 

 Ornithodoros, 275, 277, 279 

 Ornithology, 10 

 Ornithorhynchus, 480, 495 

 Orthoptera, 229, 241, 246, 250, 



255,260,261,262 

 Orycteropus, 496 

 Os coxae, 501 

 Osculum, 93, 94, 96 

 Osmosis, 23, 24 

 Osphradium, 288 

 Osprey, 453 

 Osseous labyrinth, 548 

 Ossicle, 303. 307 

 Ostariophvsida, 379, 395 

 Ostcichtliycs. 317, 325. 378-395 



(see Perca flavcsccus) 

 Ostia, 123,202,269,341 

 Ostraciontidae, 379 

 Ostracoda, 199,215, 221 

 Ostracoderms, 317 

 Ostrea, 217, 301 

 Ostriches, 433, 450, 461 

 Otoliths, 385 

 Otter, 484 

 Outbreeding, 593 



