454 



INDEX 



Mongolian race, hair of, 267 



Monkeys, and warning colors, 242; 

 prehensile tails, 223 



Monohybrid ratio, 277, 379; modi- 

 fication of, 280, 281 



Monohybrids, of peas, 277 



Monotremata, 157 



Montanian-Coloradian, 122 



Moron, 376 



Morphological variation, 265 



Moth, gipsy, 251 



Moth, geometrid larva, 244 



Moth, willow, 420 



Mountains, as barriers to dispersal, 

 257; effect on climate, 248 



Mouth parts, of insects, 138, 139 



Mouths of insects, 233; piercing and 

 sucking, 334; mandibulate, 139 



Mulattos, 362 



Mule, 345; fertility of, 349 



Muller, H. J., 314, 320, 402, 419 



Multiple allelomorphs, 314 



Mutants, in cultivated plants, 342 



Mutations, cause of, 405; in Dro- 

 sophila, 369, 404; and natural 

 selection, 404; and pure lines, 357; 

 in Oenothera, 402; theory, 428; 

 reverse, 402 



Mutilations, 386; source of, 432 



Nails, 85; of primates, 188 



Narcissus, 345, 346 



Natural history, 5 



Natural Selection, 385; answers to 

 objections, 395; examples of, 393; 

 in Angraecum sesquipedale, 393; 

 objections to theory, 395; origin of 

 theory, 385; statement of theory, 

 385; summary of, 392; underlying 

 principles, 386 



Nautilus, 132 



Neanderthal man, 204; cranial capac- 

 ity, 204; mental development, 205; 

 phylogeny, 204; speech, 205; skull 

 and skeleton, 305; stature and 

 posture, 205 



Nearctic, 356; realm, 255 



Nebraska, fossil man in, 201 



Necturus, 418; and inheritance of ac- 

 quired characters, 418; pectoral 

 girdle, 80; pelvic girdle, 77, 78; 

 sacrum, 73 



Negro, hair of, 267; white crosses, 362 



Nekton, 215; aerial, 217 



Nemathelminthes, 28 



Neo-Lamarckian theories, 422 



Neolaurentian, 124 



Neoteny, 211; in axolotl, 211 



Neotropical, 255; 356 



Nepidae, 254 



Nesomimus, 409 



Neural groove, 44; in chick embryo, 



43 

 Neural tube, 44 

 Neurenteric canal, 42, 44} 47 

 Newman, 152, 411 

 Nilsson-Ehle, 316 

 Nilsson, Hjalmar, 353 

 Non-adaptive changes, 247 

 Non-adaptive characters, 212, 434 

 North America, climate of, 248 

 Notholaena, 225 

 Notochord, 37, 51, 56, 57 

 Notonectidae, 254 

 Nucleus, 32; role in inheritance, 301 

 Nuttall, 95 



Obelia, 30, 23 



Oceans as barriers to dispersal, 258 



Ocellus, 110 



Octopus, 132 



Octoroon, 363 



Oenothera lamarckina, scintillans, ob- 



longa, lata, 402, 403; gigas, nanella, 



403 

 Oligocene, 122; amber fossils of, 127; 



elephants, 169; horses, 179; camels, 



185 

 Ommatidium, 111 

 Onohippidion, 182, 183 

 Ontogeny, 109 

 Onychophora, 136 

 Oocyte, 292 

 Oogonia, 292 

 Opthalmochlus duryi, I4I 

 Orang, 189 

 Orchesella rufescens var. pallida, eye, 



396 

 Order, 26 



Ordovician, 123; fishes, 130, 144; an- 

 nelids, 132; Brachiopoda, 132; 



vertebrates, 144 

 Organic environment, 230 

 Organic world, unity of, 416 

 Organisms, as agents in dispersal, 



261; relationships of, 232 



