636 



ANIMAL BIOLOGY 



Mouth, hydra, 137 

 infusoria, 79 

 insects, 276, 277, 278 

 lamprey, 342 

 leech, 260 

 mussel, 214 



nemathelminths, 178, 182 

 Paramecium, 69, 70 

 planaria, 159, 160 

 rotifer, 189 

 sea anemone, 147 

 sea urchin, 207 

 shark, 334 

 snake, 393 

 spider, 303 

 squid, 226 



starfish, 196, 198, 211 

 vertebrate, 327 

 Mouth cavity, 327 

 Movement, 42, 494 

 Mucous canals, 347 

 Mucojs glands, 324, 327, 365 

 secretion, 327, 341, 467, 491 

 Mud chimney, 262 

 Mud flat faunas, 511 

 Mud puppy, 370, 371 

 Mulattoes, 563 

 Mules, 504 



Muller, Johannes, 582 

 Multiple hybrid, 561 



genes, 563 

 Multiplication period, 109-112 

 Mure-, eye, 227 

 Musca domestica, 293 

 Muscle cells, 23, 31, 101, 102, 179, 180, 234, 463, 



471 

 Muscle contraction, 495-496 

 Muscle, fibers, 196 

 Muscle origin, 471 



Muscle tissue, 101, 102, 161, 327, 471 

 Muscles, 105, 106, 471, 495 

 adductor, 213, 217 

 circular, 236, 238 

 ear, 647 

 eye, 339 

 flexor, 414 

 heart, 102 

 invertor, 186 

 longitudinal, 236, 238 

 nonstriated, 102 

 retractor, 214, 217 

 sphincter, 329 

 striated, 102 

 voluntary, 326, 327 

 Muscular coordination, 408 

 Muscular energy, 482 

 Muscular movement, 495 

 Muscular system, 104, 326-327, 471 

 Mushroom coral, 164 

 Musk, 448 



ox, 439, 537 

 Muskrats, 509 

 Mussels, 212-220, 225, 232 

 Mutant, 562 

 Mutation, 560, 562 



Mutualism, 523 

 Muzzle, 424 

 Myelencephalon, 334 

 Myonemes, 85, 471 

 Myrianida, 253 

 Myriapoda, 274, 310, 311 

 Myriapods, 274, 275, 470, 542 

 Myrmeleon, 295 

 Mysis, 270, 271 

 Myxinoidea, 341 

 Myxinoids, 341-342, 470 



N 



Nacre, 214 



Naiad, 284 



Nails, 324 



Naked snails, 224 



Nares, 335 



Nasal chamber, 328 



Natural classification, 58 



Natural immunity, 519 



Natural selection, 544, 545, 549, 550 



Nauplius, 270, 271, 525 



Nausea, 473 



Nautiloids, fossil, 541 



Nautiluses, 221 



types, 226-228 

 Neanderthal man, 462, 453 

 Nearctic region, 632, 535 

 Necator americanus, 182 

 Necessity, 545, 549 

 Neck, 222, 322, 386, 403 

 Nectar, 297 

 Necturus, 370 

 Necturus maculosus, 371 



lung, 469 

 Negative response, 56 

 Negroid type, 453 

 Nekton, 511 

 Nemas, 180, 181 



Nemathelminthes, 178, 180, 674, 576 

 Nemathelminths, 178-185, 470, 489 

 Nematocysts, 137-139, 148, 150, 674 

 Nematoda, 180 



Nematodes, free-living, 180, 181, 495 

 Nemertinea, 186, 574, 576 

 Nemertines, 184-186, 465, 469, 470, 495 

 Neornithes, 409 

 Neoteny, 380 



Neotropical region, 532, 534 

 Nephridia, 193, 236, 238, 273, 319. 470, 494 

 Nephridial system, 321 



tubules, 331 

 Nephridiopore, 236, 237, 250 

 Nephros, 470 



Nephrostome, 236, 237, 332 

 Nereis, 247 

 Nereis virens, 247 

 Nerve, 100, 160, 161 



cells, 23, 31, 102, 103, 139, 243, 472 



center, 168 



cord, 124, 160, 196, 201, 259, 310, 321, 384 



endings, 324 



fibers, 102, 103, 138 



