INDEX 



397 



minnows, 167 



mites, 81-83 



molecules, 233, 234 



moles, 216 



molluscs, 98-107 



molt, 21 



molting, 10, n, 21, 71, 72, 89 



monarch butterfly, 23 



monkeys, 227, 228 



Monotremes, 211, 212 



moose, 222 



morphology, 232, 355 



mosquitoes, 45-48, 148, 150 



moths, 25-30 



motor area, 302, 303 



motor nerves, 296-298 



motor reflex, 144 



Musca domestica, 40, 41, 42 



muscles, 243, 291-293 



Muscular tissue, 243 



mussels, 102 



mutations,"356 



My a arenaria, 102 



Myriapoda, 75, 76 



N 



Nam Family, 380 



narcotics, 257' 



natural selection, 360-362 



nauplius, 94 



nautilus, 105, 106 



Necturus, 170 



nematocysts, 131, 136 



nematodes, 122-124 



nephridia, 117 



nerve cells, 296 



nerve cord, of Amphioxus, 155, 156 



of Balanoglossus, 155 



of crayfish, 88 



of earthworm, 118, 156 



of grasshopper, 8, 9 



of tunicate larva, 154 

 nerves, 294-299 



nervous system, of Amphioxus, 155 

 156 



of clam, 100, 101 



of crayfish, 88 



of earthworm, 118 



of grasshopper, 8, 9 



of man, 294-303 

 nervous tissue, 244 

 nests, 189, 191-194, 197, 338, 339 

 nettling cells, 131 

 newts, 169 



nitrogen, 234, 236, 237, 238 

 Noctuidae, 28 

 notochord, 154-159 

 Notonecta, 33 



Novius (Vedalia) cardinalis, 38, 54 

 nuclei, 142, 241 



ocelli, 3 

 Octopus, 107 

 oil glands, 283, 284 

 olfactory pits, 3 

 operculum, 158-160 

 Ophidia, 176 

 Ophiurans, no 

 opossum, 214 

 orang-utans, 227 

 organs, 240 



Ornithorynchus, 211, 212 

 orthoceratites, 105 

 Orthoptera, 1-16', 18, 19, 51 

 osculum, 139 

 ossicles, 87 

 ostia, 88 

 ova, 333 

 ovaries, 9 

 oviduct, 9 

 ovipositor, 5, 14, 19 

 owls, 204, 206, 207 

 ox, 220 



oxidation, 235, 239, 270 

 oxygen, 234, 235-239, 260, 269, 

 271, 273, 275, 276 



