57^ 



INDEX 



Nelson, 144 



Nemas, 87-99; characteristics, 87; classi- 

 fication, 87; longevity, 88 



Nemathelminthes, 87 



Nematocysts, 54, 55, 57 



Nemerteans, 85 



Nemertean Theory, 220 



Neornithes, 334 



Neoteny, 268 



Nephridiopore, in 



Nereis, loi 



Nerve cells, 424 



Nerve net in Coelenterates, 67 



Nervous system, earthworm, 112; lobster, 

 166 



Nervous system of ascaris, 90; of birds, 

 364; of mammals, 464-480 



Nest and eggs of humming bird, 351 



Neuritis optica, 535 



Neuroblasts, 495 



Neuro-epithelium, 425 



Neuroptera, 185 



Neurotoxin, 328 



Nicotine, and the goat, 481 



Nictitating membrane in various animals, 



529 



Nietzsche's super-man, 515 

 Nighblindness, 535 

 Nile goose, 495 

 Nile monitor, 312 

 Nine-banded armadillo, 397 

 Noctiluca scintillans, 27 

 Noguchi, 328 

 Non-disjunction, 539 

 Non-striated, 426 

 Nordics, 417 

 Norman, 135 

 Norris, H. W., 237 

 North American beaver, 392 

 North American otter, 385 

 North American prong-horn, 404 

 Northern fur seal, 389 

 Nose monkey, 413 

 Notochord, 209 

 Nuclear membrane, 7 

 Nuclear substance, 5CX3 

 Nucleolus, 7 



Nucleus, 7 

 Nummulites, 25 



OBELIA, 58, 59 



Ocelot, 380 

 Odonata, 179 

 Odontoglossae, 340 

 Ogliole, 64 



Old World monkeys, 413 

 Olfaction in the bee, 207 

 Olfactory sense, 476 

 Oligotrichida, 30 

 Omasum, 434 

 Ommatidia, 168 

 Onager, 491 

 Onychophora, 175 

 Oogenesis, 500, 505 

 Operculum, 152 

 Ophidia, 313 

 Ophiuroidea, 135 

 Ophryoscolecidae, 30; 482 

 Opisthoglypha, 316 

 Opossum, 376 

 Orb weaver, 202 

 Orca, 410 



Organ of Bojanus, 145 



Organ of Corti, 475 



Organ formation, 508 



Organic sensations, 477 



Organs of internal secretion, 444 



Organs that man can lose, 480 



Orohippus, 491 



Oroteidae, 268 



Orthoptera, 180 



Osborn, H. F., 416, 510 



Osburn, R. C, 128 



Osculum, 50 



Osmotic pressure, 5 



Osphradium, 147 



Ostia, sponge, 50; grasshopper, 183 



Ostracoda, 170 



Ostrea, 150 



Ostrich, 335 



Otocysts, molluscan, 147 



Ovaries, 55, ni 



Ovary, 444 



Ovum of the cat, within the ovary, 462 



Owl monkey, 412 



