602 



INDEX' 



and sensory, 162, 169, 334; 

 sciatiq, 62, 162, 515; spinal, 

 i6oj 409, 445, 515, 568; sym- 

 pathetic, 162, 445, 516; vaso- 

 motor, 174 ; visceral, 366 



Nervous impulse, 62, 154 



Nervous system : Frig, 155; Hydra, 

 298 ; Bougainvillea, 311; Earth- 

 worm, 333 ; Crayfish, 365 ; Mus- 

 sel, 392 ; Lancelet, 404, 408 ; 

 Dogfish; 442 ; Rabbit, 511; de- 

 velopment of, in Vertebrates, 565, 



Neural arch, spine, and canal, see 



■ Vertebra 



Neural plate and process, 424 



Neuraxis, 167 



Neurenteric canal, see Canal 



Neurilemma, 167 



Neurocoele, 443 ; and see Canal, 

 central of spinal cord, and Ven- 

 tricles of brain 



Neuroglia, 169 



NeWt, 218 



Nictitating membrane, 5, 469 



Nodes of nerve-fibre, 167 



Nose, see Olfactory organ 



Nostrils, 5, 17, 180, 416, 448, 468, 



470, 517 

 Notochord, 203, 404, 425, 560, 



,576. ss? 



Nuclear division, 544, ' s^S > in- 

 direct, 545 

 Nuclear membrane, 542 ; spindle, 



544 

 Nucleolus, iO')etseq., 541, 542 

 Nucle.us, io5 -i seq., 129, 231, 243, 



254, 265, 269, 273 

 Nucleus, conjugation-, 268 ; s^- 



mentation-, 554 

 Nutrition, 67 ; and see uiider various 



types 



o. 



o 



rbelia, 317 

 Occipital condyle, see Skull 

 Ocellus, see Eye-spot 

 Oesophagus, see Gullet 



Odontoblasts, 429 

 Odontoid process, 482 

 Olecranon, 49, 485 

 Olfactory capsule, 39, 42, 420, 476 

 „ lobe, 160, 444, 511, 514, 



568 

 ,, organs ; Fro^, 180 ; Cray- 

 fish, 367 ; Mussel, 394 ; Dogfish, 

 416, 448 ; Rabbit, JII, 517 ; de- 

 velopment of, in Vertebrates, 569 

 Olfactory pit, 408 

 Oligochseta, 341 

 Ommatideum, 366 

 Ontogeny, 224 

 Oogenesis, 196, 548 

 Oosperm, 198 ; and see under 



various types 

 Oosperm, holoblastic and mero- 



blastic, 556 

 Opalina : occurrence and general 

 characters, 269 ; structure and 

 division of nuclei, 269 ; parasitic 

 nutrition, 271 ; reproduction, 

 271 ; means of dispersal, 272 ; 

 development, 254 ; practical di- 

 rections, sSy 

 Optic chiasma, see Chiasma ; cup, 

 570; lobe, 157, 443, S13. 566; 

 thalamus, 159; vesicle, 569 

 Oral cavity, see Buccal cavity 

 Oral hood, 406 

 Orbit, see Skull 

 Order, 218 



Organ, 30, 151, 238, 335 

 Organism, 231 

 Origin of muscles, 60 

 ,, of species. 225 

 Osmosis, see Diffusion 

 Osphradiiim, 394 



Ossicles: of gizzard (Cra;y{>A). 358, 

 S76 ; auditory (Rabbit)., see Audi- 

 tory ossicles 

 Ossification, 44 



Ostia : of heart, 362 ; of gills, 389 

 Otocyst, 3^4 

 OtoUths, 188 

 Ovary : Frog, 23, 193, 195 ; and see 



Reproductive organs 

 Oviduct, 25, 196, 337, 368, 453, 

 523, 574 



