470 



INDEX 



Born, development of eggs in a 

 fixed position, 135 



Boveri, observations on fertilisation 

 of egg in Ascai'is, 23; function 

 of the centrosomes, 25 ; observa- 

 tions on the egg of the sea-urchin 

 artificially deprived of its nucleus, 

 28; chromosomes of Ascafis 

 niegalocephala, 86; differentia- 

 tion of somatic cells of Ascaris 

 niegalocephala, 191 ; number of 

 nuclear rods in two species of 

 Ascaris, 241; view concerning 

 idants, 242 



Brandza, examination of hybrids 

 with regard to parental charac- 

 ters, 270 



Brooks, W. K., on the laws of 

 heredity, 9; on variation, 412; 

 on the non-transmission of ac- 

 quired characters, 396 



Briicke, Ernst, on ' Elementar 

 organismen,' 2; on ultimate vital 

 particles, 20; on albumen, 38; 

 on the organic nature of proto- 

 plasm, 39 



Bryophyllum, budding in, 211 



Bud-variation, 436; theoretical ex- 

 planation of, 441 



BUtschli, investigations on the proc- 

 esses of nuclear division, 23; 

 the polar bodies correspond to 

 aborted ova, 251 



Butterflies, the markings on the 

 wings of, as confirming the theory 

 of determinants, 54, 174, 264, 

 265; Kallima pa^-allecta as an 

 example of relative perfection, 

 272; the origin of climatic varia- 

 tions in the idioplasm, 379, 399, 

 407, 418 



Cardamine pratensis, budding in, 



211 

 Carneri, observations on telegony, 



Caspary, experiments in crossing 

 Cytisiis laburnum and C. pur- 

 pureus, 343 



Castration, as a cause of sexual re- 

 version, 358 



Cecidomyia poae, formation of galls, 

 221 



Centrosome, with its sphere of at- 

 traction, is an apparatus for the 

 division of the cell and nucleus, 

 23; continuity of the centrosome, 

 48 



Chabry, experiments on eggs of 

 Ascidians, 136 



Chromatin, the hereditary substance, 

 24, 26; must be different in each 

 kind of cell, 32 



Chromosomes correspond to the 

 idioplasm, 10 ; their form, 24; 

 spoken of as idants, 67 



Continuity of the germ-plasm, his- 

 torical account of, 198 



Control of the cell, 45 



Cuttings, development and origin 

 in the idioplasm of, 212 



Cyclops, observations on segment- 

 ing ova, 191 



Cymathoidce, temporary sexual di- 

 morphism, 1 1 1 



Cypris reptans, markings on the 

 shell in their relation to the theory 

 of determinants, 88; reversion 

 in, 344; theoretical explanation 

 of reversion in, 347 



Cytisus adami, 339; theoretical ex- 

 planation of the variation in, 344 



Daphnia pulex, alternation of gen- 

 erations in, 175 



Daphnidce, embryogeny of, 184; 

 secondary nature of the differen- 

 tiation of germ-cells of, 186; 

 germ-track of, 192 



Darwin, Charles, 'pangenesis,' 2; 

 ' gemmules,' 3; comparison of 

 the * gemmules ' with Spencer's 

 ' physiological units,' 6; on cor- 

 related variations, 84; on the white 

 coloration in animals and plants, 

 277; on breeding, 291; on the 

 force of heredity in cattle, 293; 

 on reversion in plant-hybrids, 299; 

 on reversion to remote ancestors, 

 316; on reversion in pigeons, 

 323; in mules, 328; in Antir- 

 rhinuiii ?iiajiis, t^^i; experiments 

 on crossing Cytisus laburnum- 



