866 



INDEX 



Nerve transmission, membrane theory of, 



104 

 Nervous system, 574 



autonomic, 418, 593 



central, 596 



divisions of, 588 



organization of, 585 



peripheral. 591 

 Neural arch. 399, 508 

 Neural canal. 399 

 Neural crest. 641 

 Neural folds, 420 

 Neural gland, 386 

 Neural pathways, 590 

 Neural spine, 399 

 Neural tube, 130, 641 

 Neurilemma, 61 

 Neurofibrils, 104. 162 

 Neurogenic rhythms, 335 

 Neuroglia, 61, 585 

 Neurohormones, 111 

 Neurohumors, 106, 596, 620 

 Neuromuscular junction, 101 

 Neurons, 60, 585 

 Neuropodium, 272 

 Neuroptera, 837 

 Neurosecretion, 328 

 Neurospora, 687, 707 

 Neurotoxic poison, 460 

 Neurulation, 641 

 Neutralism, 763 

 Neutrophils, 59, 542 

 Niacin, 527, 528 



Nictitating membrane, 454, 579 

 Nile bichir, 440 



Nitrogen cycle, 757 



Nitrogen fixation, 758 



Nitrogenous wastes, 559 



Noddy terns, 480 



Nodes of Ranvier, 61 



Nonelectrolytes, 23 



Norepinephrine. 617 



Notochord, 130, 382, 383, 387, 390, 429, 641 



Notonecta, 755 



Notopodium, 272 



Notostmca, 303, 836 



Notum, 308 



Nuclear reactor, 20 



Nucleic acids. 29 



Nucleolus, 37 



Nucleoplasm. 14 



Nucleotide, 29 



Nucleus, 14, 35 

 role of, 35 



Nuda, 832 



Nudibranchs, 251, 834 



Nummulitidae, 159 



Nutrition, holozoic, 78 



types of, 78 

 Nymphs, 315 



Obelia, 190. 191. 833 

 Occipital condyles. 397, 509 

 Oceanic islands, fauna of, 734 

 Oceanodroma, 841 

 Ocellus. 311, 322, 386 

 Octopoda, 834 

 Octopus, 263 



psychologic studies of, 265 

 Oculomotor nerve, 417 

 Odonata, 313, 837 

 Odontoceti, 842 

 Odontognathae, 481, 841 

 Olfactory bulbs, 416, 597 

 Olfactory epithelium, 108, 414 

 Olfactory nerves, 417 

 Oligocene epoch, 725 

 Oligochaeta, 269, 834 

 Omasum, 519 

 Ommatidia, 110, 297, 336 

 Omnivores, 79 

 Oncosphere, 217 

 Ontogeny, 644, 730 

 Onycophora, 323, 835 

 Oocytes, primary, 120 

 Oogenesis, 1 20 

 Oogonia, 120 

 Ootid, 122 

 Oparin, A. I., 710 

 Opercular chamber, 529 

 Operculum, 252, 320, 420. 438 

 Ophidia. 460, 840 

 Ophiocistioidea, 838 

 Ophisaurus, 459 

 Ophiuroidea, 375, 838 

 Opiliones, 835 

 Opisthobranchia. 251, 834 

 Opisthonephros. 560 

 Opisthosoma, 320, 322 

 Opossum, 492 

 Optic chiasma, 417, 597 

 Optic lobes, 416, 597, 600 

 Optic nerves, 417. 577 

 Optic tracts, 417 

 Oral groove, 80 

 Oral hood, 387 

 Oral suckers, 420 

 Oral valves, 529 

 Orang-utan. 495. 741, 742 

 Orbits, 397, 510 

 Order, 141, 143 

 Ordovician period, 721 

 Organ, 34 



Organ of Corti, 584 

 Organ systems, 34 

 Organelle, 149 



conductile, 150 

 Organic compounds, 24 

 synthesis in vitro, 711 



