884 Index 



Neurilemma, 54, 54* 



Neurofibril, 47, 459, 498,* 505 



Neuroglia, 845 



Neurohumor, 501 



Neuromotor apparatus, 352* 



Neuron (nerve cell), 47, 54, 54,* 501 



Neutron, 79,* 80, 81,* 83* 



Newt, 333,* 334* 



Nictitating membrane, 438 



Nissl granule, 47, 54* 



Nitrogen, 79,* 650, 651 



fixation, 169, 650, 651, 664 

 Noctiluca, 763 



Node of Ranvier, 54, 54,* 845 

 Nodus, 412* 



Nondisjunction, 680 {see also Heredity) 

 Nonelectrolyte, 751, 845 

 Nonmedullated {see Nerve) 

 Nosema, 534 

 Nostoc, 113,* 154 

 Nostril, 328,* 331, 331,* 332,* 421, 



424, 434 

 Notochord, 325-343, 326,* 327,* 328,* 

 329, 332,* 447, 449* 



Nucellus, 201-203, 225 

 Nuclear framework, 40,* 43-44 



membrane, 40,* 43, 62, 63,* 65-67 



sap, 44 

 Nucleolus, 40,* 44, 62, 66* 

 Nucleolymph, 43-44 

 Nucleoplasm, 40,* 44 

 Nucleus, 40,* 43-44, 62, 65, 66,* 70, 

 143, 153-156, 156,* 157-162 



of the atom, 79,* 80, 81,* 83* 



Nuda, 293 



Nurse cell, 709 



Nutrition, autotrophic, 120, 168 



chemosynthesis, 120 



heterotrophic, 119, 120, 167, 168 



holophytic, 359 



holozoic, 836 



parasitic, 120 



photosynthetic {see Photosynthesis) 



saprophytic, 120, 123, 125 

 Nymph, 398, 411, 412,* 419 



O 



Obelia, 285,* 289 



Obligate, 846 



Ocellus, 393, 394,* 398, 406 



Octopus, 311, 316,* 542 



Oestrone {see Endocrine glands) 



Ogliole, 536 



Oil, 153, 159 



from plants, 259, 267 

 Olfactory equipment, 311,* 398, 405, 



424, 439, 447, 505 {see also 



specific organisms) 



OHgochaeta, 308 

 Ommatidia, 397 

 Omnivorous, 846 



Onion root, 68,* 69,* 71 {see also 

 Mitosis) 



Ontogeny, 442, 742 

 Onychophora, 318, 324* 

 Oocyst, 365,* 367 

 Oocyte, 709, 710* 



Oogamy, 115, 118, 119, 130, 154, 155, 

 161, 187 



Oogenesis, 709, 710* 

 Oogonia, 161, 162, 174,* 175, 709, 

 710* 



Ookinete, 365,* 366 

 Opahna, 534, 534* 

 Operculum, 303 

 Opsonin, 520 

 Optic chiasma, 496* 



lobe {see Brain) 



nerve, 497, 497* 

 Oral groove, 350, 350* 

 Orbit, 79*, 81, 81,* 83,* 427, 438* 

 Organ, 55, 60, 647 

 Organelle, 274 {see also Protozoa) 

 Organicism, 847 



Organisms, continuity of, and descent 

 with change (evolution), 732- 

 749 



Organization, 97, 100 

 Oriental region, 598 

 Orientation, 847 

 Origin of Hfe, 732-735 

 Orthogenesis theory, 847 

 Orthogenetic variation, 724 

 Orthoptera, 393-398 

 Oscillatoria, 113,* 152, 154 

 Osculum, 281,* 284* 

 Osmosis, 38, 752, 753, 753* 

 Osmotic pressure, 226, 752, 753, 753* 

 Ossicle 302* 



Ostium', 282,* 284,* 291,* 321,* 324,* 

 425,* 395, 514 



Otolith, 496 



Outbreeding, 703 



Ovary, 143, 144,* 145,* 146,* 207-217, 

 223,* 225, 225,* 286,* 292, 

 296,* 299,* 321,* 328,* 332,* 

 371-383, 389,* 439,* 440, 450, 

 507,* 509, 512, 514, 515* 



Oviduct, 299,* 311,* 312,* 320,* 321,* 

 332,* 371-378, 389,* 391, 

 396,* 398, 406, 427,* 439,* 

 514 



Oviparous, 847 

 Ovipositor, 394,* 398 

 Ovotestis, 311,* 312* 

 Ovoviparous, 847 



