INDEX. 



469 



in two sexes of, 59; partheno- 

 genesis of, 302. 



Pieris napi, length of life of, 44. 



Pig, length of life of, 6. 



Pigeon, length of life of, 36; cross- 

 breeding of, 341. 



Pike, length of life of, 6. 



Pisidium, length of life of, 57. 



Planorbis, length of life of, 57. 



Plants, duration of life of, 33, 

 66. 



Polar bodies, 192, 222, 250; the 

 significance of, 216, 230, 349; 

 of Sponges, 222 ; in partheno- 

 genetic eggs, 255, 355, 394; of 

 Rabbit, 349 ; number of, 356 ; 

 significance of second, 363, 373 ; 

 in plants, 389. 



Pole-cells, of Diptera, 200. 



Polistes gallica, 'workers' of, 54; 

 length of life of males and fe- 

 males, 54. 



Pollen-grains, 227. 



Polyphemus, spermatozoa of, 178 ; 

 summer eggs of, 244 ; polar 

 bodies of, 355. 



Polyplastides, definition of, 120, 

 123, 125, 161 ; development of, 



154- 

 Polyzoa, length of life of, 58. 



Poulton, on colours of caterpillars, 

 406 ; on cats with supernumerary 

 toes, 439. 



Proteus, 87. 



Protomyxa aurantiaca, 151. 



Protozoa, development amongst, 

 152 ; conjugation of, 294. 



Psorosperms, 151. 



Psychidae, length of life of, 16, 

 44, 45, 159; deposition of eggs 

 of, 18 ; death of female, 64, 133 ; 

 parthenogenesis of, 301. 



Pulex irritans, length of life of, 42. 



Pupa, length of life of, 56. 



Rabbit, polar bodies of, 349. 

 Rauber, on heredity, 174. 

 Ravens, length of life of, 36. 

 Regeneration of lost parts, 66 ; 



in Infusoria, 188 

 Rejuvenescence, 112, 116, 125, 



i33i 155. 289. 

 Reproduction, original form of. 



122 ; effect of monogonic, 280, 

 282 ; amphigonic, 286, 288, 294, 



Reproductive cells, 28, 29, iii. 



Rhodites rosae, parthenogenesis 



of, 334- 



Richter, on inheritance of acquired 

 characters, 451. 



Robin, on pole-cells of Diptera, 

 200. 



Rolph, on conjugation, 293. 



Romanes, on correlation, 401. 



Roth, on heredity, 169, 171. 



Rotifera, unequal length of life in 

 two sexes of, 59 ; polar bodies 

 of, 360. 



Roule, on origin of ova, 226. 



Roux, on the struggle of the parts 

 in the organism, 88, 102 ; on de- 

 velopment in altered conditions, 

 179; on forces controlling nu- 

 clear division, 236, 373; on karyo- 

 kinesis, 370. 



Rudimentary organs, 89 ; disap- 

 pearance of, 298 ; not found in 

 parthenogenetic forms, 301. 



Rumia Crataegata, 406. 



Sachs, on reproduction in Mosses, 

 216 ; on venation, 266, 318 ; on 

 shoots of clirnbing Ivy, 405, 

 412. 



Sagitta, segmentation of ^^^ of, 

 74, 202. 



Saperda carcharias, length of life 

 of imago of, 47. 



Sarcophaga carnaria, length of 

 life of, 43. 



Saturnia pyri, length of life of, 

 45 ; S. carpini, cocoon of, 95. 



Saturnidae, habits of, 44. 



Saw-flies, ancestors of bees and 

 wasps, 20 ; length of life of 

 imago of, 49, 60. 



Schmidt, on malformations of the 

 ear, 452. 



Schneider, on instincts of per- 

 ception, 93, 95. 



Schultze, on polar bodies of Am- 

 phibia, 350, 362. 



Scytosiphon, male partheno- 

 genesis in, 253. 



Sea-gulls' eggs, 38. 



Senility, 21, 22, 32, 159. 



