482 



INDEX OF SUBJECTS 



Oxychromatin, 38, 303; staining-reactions, 



337- 

 Oxydation-ferments, 351. 



Oxytricha, 342. 



Oyster, germ-nuclei, staining-reactions, 175. 



Pallavicinia, reduction, 275. 



Paludina, dimorphic spermatozoa, 141. 



Pangenesis, 12, 290, 431. 



Pangens, 291. 



Parachromatin, 41. 



Paralinin, 41. 



Paramceba, mitosis, 94, 315. 



Paramcecium,vci\\.o^\%,^\; conjugation, 224; 

 reduction, 277. 



Paranucleus, 163. 



Parthenogenesis, theories of, 281; polar 

 bodies in, 280. 



Pellicle, 54. 



Peniatoma, 271. 



Pet7-omyzon, fertilization, 192, 212. 



Phallusia, fertilization, 193, 212. 



Physa, fertilization, 193, 2IO, 212; reversed 

 cleavage, 368. 



Physiological units, 289. 



Pieris, spinning-gland, 37. 



Pigment-cells, 102. 



Piltdaria, fertilization, 216. 



Pinus, reduction, 275. 



Planaria, regeneration, 394. 



Plant-cells, plastids, 52; membranes, 54; 

 mitosis, 82; cleavage-planes, 363. 



Plasma-stains, 335. 



Plasmocyte, 52. 



Plasmosome, 34. 



Plasome, 291. 



Plastids, 52; of the ovum, 133; of the sper- 

 matozoid, 143; conjugation of, 229. 



Plastidule, 29 1. 



Plastin, 41, 331. 



Pleurophyllidia, 78, 94. 



Podophyllum, 267. 



Polar bodies, 181 ; nature and mode of for- 

 mation, 235-240; division, 236; in par- 

 thenogenesis, 281. 



Polar rings, 156, 202. 



Polarity, of the nucleus, 36; of the cell, 55; 

 of the ovum, 378; determination of, 382. 



Pole-plates, 91. 



Pollen-grains, formation, 263-265. 



Pollen-tube, 218. 



Polyclades, cleavage, 416. 



Polychcerus, 276, 325. 



Polygordiiis, cleavage, 368. 



Polyspermy, 198; prevention of, 199. 



Polystomella, regeneration, 344. 



Polyzoniutn, 159. 



Porcellio, amitosis, 116. 



Predelineation, 398. 



Preformation (see Evolution), 



Pressure, experiments, 375, 410. 



Principal cone, loi. 



Pristiurus, 338. 



Promorphology (see Cleavage, Ovum). 



Pronuclei, 202. 



Prophase, 65. 



Pi-osthecer(Eus, 213, 235, 256, 259, 306. 



Prosthiostomu7n, 212. 



Protamin, 334. 



Proteids, 331. 



Prothallium, 264; chromosomes in, 275. 



Protoplasm, 4, 5, 17, 19; structure, 23,42, 



293; chemistry, 331. 

 Protoplast (see Plastid). 

 Pseudo-alveolar structure, 50. 

 Pseudo-reduction, 248. 

 Pieris, 253. 



Pterotrachea, germ-nuclei, 186, 205. 

 Ptychoptera, spireme-nuclei, 35. 

 Pygcera, 165. 

 Pyrenin, 41. 

 Pyrenoid, 133. 

 Pyrrhocoris, 165, 248. 



Quadrille of centres, 210. 



Rat, spermatogenesis, 170. 



Reduction, general outline, 234; parallel 

 between the two sexes, 241 ; theoretical 

 significance, 243; detailed account, 246; 

 in plants, 263; Strasburger's theory of, 

 275; in unicellular forms, 277; by conju- 

 gation, 257; modes contrasted, 247. 



Regeneration, Weismann's theory, 406; in 

 frog-embryo, 409; nature of, 425, 427; 

 in coelenterates, 430; of lens, 433. 



Rejuvenescence, 179, 224. 



Renilla, ovum, 132. 



Rhabdonetna, amitosis, 115. 



Rhvnclu'ltiiis, fertilization, 192, 193, 212; 

 cleavage, 370. 



Rotifers, sex, 145. 



Sagitta, number of chromosomes, 184; pri- 

 mordial germ-cells, 146; germ-nuclei, 184; 

 spermaster, 191. 



Salamander, epidermis, 3; spermatogonia, 

 20; mitosis in, 71, 78; pathological mito- 

 sis, 98; leucocytes, 102; spermatozoa, 

 1 40; maturation, 259. 



