938 



INDEX 



Muscular or contractile tissue, lOG 

 system, 1C9 



chicken. 612 



frog-, .523 



phrynosoma, 576 

 Musculium ferrissi, 248 

 Musculocutaneous vein. .508 

 Musli ox, 631 



turtle, 549 

 Muskrats, 622, 625 

 Mustelus canis, 425 

 Mutation theory, 887 

 Mutations, 836 

 Mutualism, 735 

 Mycetozoa, 69 

 Mylohyoid muscle, 408 

 Myocomma, 370 

 Myocytes, 125 

 Myoflbrils, 106 

 Myology, 644 

 Myosepta, 496 

 Myoseptum, 370 



Myotomes, 370, 372, 427, 496, 537 

 Myriapoda, class, 265, 287. 289 

 Myrmecophaga jubata, giant anteater, 



621 

 Myrmecophiles, 339 

 Myrmeleonidae, family, 322 

 Mysis, 285 



Mystacoceti, order of whales, 634 

 Myxedema, 669 

 Myxidium, 73 

 Myxine, 412 

 Myxinidae, family, 412 

 Myxinoidea, subclass, 412 

 Myxobolus, 73 

 Myxosporidia, 73 

 Myzus cerasi, 318 



N 



Nabidae, family, 318 



Nabis ferus, 318 



Nacreous layer, 250 



Nagana, 80 



Narwhal, 634 



Nasal bones, 465 



Natural resources, restoration, 794 



selection. 885 

 Naturalists of the frontier. 48 

 Nauplius larva, 285 

 Nautilus. 258 

 Navel, 820 

 Nearctic region, 712 

 Necator, 750 



hookworm, 745 

 Nectocalyces, 137 

 Necturus, 485 



circulatory system, 490 



digestive system, 489 



internal structure, 488 



maculosus, 487 

 muscular system, 496 

 respiratory system, 491 

 skeleton, 494 

 urinogenital system, 492 

 Neelidae, family, 312 

 Nekton. 769 

 Nemathelminthes. 26, 745 



phylum, 175 

 Nematocyst, 134 



Nematocysts, 136, 1.3S. 142, 147, 148 

 Nematoda, class, 175 

 Nematode, 750 



Nematognathi, suborder, 4.50 

 Nemertina, class, 161 

 Nemertinea, 27, 192 

 Neoceratodus fosteri, 455 



Neocomatella, 225 

 Neoechinorhynchus emydis. i7S 

 Neoscona benjamina, 296 

 Neotropical region, 713 

 Nephridia, 110, 188. 195, 206. 207. 214, 39S 

 Nephridial ducts, 189 

 Nephridiopore, 195, 206, 207 

 Nephridiopores, 201 

 Nephridium, 203 

 Nephrostome, 195, 199, 206. 207 

 Nephrostomes, on frog kidney, 514 

 Nereis virens, 195, 196 

 Nerves, cranial, of frog, 529 

 Nervous function, 404 

 system, 110 



of bullhead (ameiurus), 469 



of cat, 650 



chicken, 607 



development, 536 



of frog, 525 



phrynosoma. 573 



starfish. 233 



sympathetic, 528 



toad, 543 



vertebrates. 399 

 tissue. 107 

 Nettling cells, 135 

 Neural arch, 465 

 folds, 536 

 plate, 536, 815 

 tube, 537, 817, 818 

 Neurocoele, 372, 527 

 Neuroepitlielial, 404 



cells, 153 

 Neuron, 107 

 Neurones, 405 

 Neuropodiuni, 196. 197 

 Neuroptera, order, 266, 322 

 Neutrons, 698 



Newt, common (triturus). 484 

 Nicotinic acid. 389 

 Nictitating membrane, 562, 600, 639 

 Nidamental gland, 262 

 Nidicolae, 615 

 Nidifugae, 615 

 Night lizards. 554 

 Nipples, 653 

 Nitrogen cycle. 29 

 Noctiluca, 67 

 Noctuidae, family, 327 

 Nodosaria hispida. 69 

 Nomenclature, binomial system, 22, 43 

 Notochord, 360, 372 

 Notonectidae, fnmily, 318 

 Notopodium, 197 

 Nuclear membrane, 59, 60 

 Nuda. 157 



Nutritive-muscular cell, 151 

 Nymph. 319 

 Nysius ericae, 318 



O 



Oak-deer biome. 726 

 Obelia, 113, 131. 132 

 Occipital condyle. 494 

 Ocean, conditions, 771 

 Ocelli, 301, 345 

 Ocelot, 629 

 Ocular plate, 221 

 Oculina, 142 

 Oculomotor nerve, 527 

 Odobenus, walrus, 629 

 Odocoileus, deer, 630 

 Odonata, order. 265. 320 

 Odontoceti, order of whaler, 634 

 Odvnerus dorsalis, 335, 359 

 Oestridae, family, 330 



