INDEX 



491 



nail, 401. 



Nais, 176. 



nasal cavities, 258, 261. 



Nautilus, 165, 166. 



nectar, 64. 



Nemathelminthes, 7, 178-182. 



nematocysts, 200, 201. 



nephridia, 169, 170, 172. 



nephrostome, 170, 172. 



Nereis, 176. 



nerves, cranial, 259; motor, 259; sen- 

 sory, 259. 



nervous system, 239, 407-4O8 ; central, 

 256; of earthworm, 169, 170, 172; of 

 frog, 256-261; functions of, 259; of 

 grasshopper, 12, 17-18; peripheral, 

 256; of Planaria, 184; sympathetic, 

 260; of turtle, 311. 



nests, of birds, 354. 



neuron, 259, 260. 



Neuroptera, 108. 



newt, 300. 



nighthawk, 368, 372. 



Nosema, 230. 



nostril, 275. 



nucleus, 219, 220, 222, 223, 239, 240. 



nudibranch, 163, 164. 



nutrition, holophytic, 224; holozoic, 224. 



nymph, 19. 



octopus, 164, 1 66. 



oesophagus, of crayfish, 132, 134; of 

 frog, 247; of grasshopper, 12, 13; of 

 mussel, 147, 150. 



olfactory capsules, 254. 



olfactory organs, 17, 160 (see sense 

 organs) . 



OUgoch&ta, 177. 



omnivorous animals, 406. 



ophthalmia, 80. 



opossum, 420. 



optic lobes, 258, 259 (see brain, and ner- 

 vous system). 



oral groove, 218, 219. 



orang-utan, 446, 448. 



orbits, of eye, 408. 



order, 104. 



organs, 237, 239. 



oriole, 375, 380, 383. 



Orthoptera, 108. 



osculum, 2ii,212. 



osprey, 385. 



Ostrea, 153. 



ostrich, 377. 



otter, 425-426, 455. 



ovaries, of frog, 262, 264 ; of Hydra, 199, 



200 ; of mammals, 410 ; of mussel, 147, 



151 (see reproduction), 

 owl, 388, 467; great horned, 367, 371, 



379 ; screech, 366, 3%. 

 ox, 436, 439, 451. 

 ox botfly, 50, 51. 

 oxen, musk, 439. 

 oxidation, 251. 

 oyster, 153-155, 194. 

 oyster drill, 163, 164. 



paddlefish, 279, 280. 



pancreas, 253. 



pancreatic juice, 247. 



panther, 429. 



Paramecium, 218-221. 



paramylum, 224. 



parasites, of domestic animals, 48-56; 

 external, 4 ; habitats of, 3 ; internal, 

 4 ; intestinal, 178 ; of man, 48-56 ; 

 transmission of, 229. 



parasitic, insects, 71-72 ; Protozoa, 226, 

 227; worms, 80. 



Parks, National, 465, 466. 



paroquet, 371, 464. 



parrot, 371, 383. 



Pasteur, 475, 477. 



peacock, 381. 



pearl buttons, 166. 



pearls, 167. 



pebrine, 230. 



pectoral girdle, 255. 



pectoralis muscle, 256, 257. 



Pelecypoda, 157, 167. 



pelican, 363, 365. 



pelvic girdle, 255. 



penguin, 362, 363. 



perch, 271-277 ; habitat of, 272 ; loco- 

 motion of, 272 ; pike, 292; protection 

 of, 273 ; reproduction of, 275-277 ; 

 respiration in, 275 ; sense organs of, 

 274; yellow, 285. 



perching, of bird, 343. 



pericardial cavity, 147, 151. 



periostracum, 148. 



periwinkle, 163, 164. 



peroneus muscle, 256, 257. 



petrel, stormy, 365. 



