INDEX 



(The numbers in black-faced type refer to pages with illustrations.) 



Achromatic figure, 51 



acrosome, of spermatozoon, 98 



Actinophrys, conjugation, 192; matu- 

 ration, 166; plastogamy, 189 



Acttnosphcerium, chromosome num- 

 ber, 66 



Adolphi, 166 



agglutination, of spermatozoa 167 



alecithal ova, 93, 226 



allantois, 351 



allosome, 310 



alveoli, of protoplasm, 36 



Amblystoma, spermatophore, 105 



Ameiurus, gastrula, 343 



Amia, cleavage (incomplete), 241 



amitosis, 43 



amnipn, 351 



Amniota, 351 



Amceba, autogamy, 191; conjugation, 

 192; cytotropy, 189; fission, 2; 

 karyosomes, 60, 61 



Amceba diploidea, maturation di- 

 visions, 160 



amphiaster, 51; mechanism of for- 

 mation, 80 



Amphibia, blastula, 331; gastrula- 

 tion, 339, ff.; 341 



amphigony, 12 



amphimixis, 213 



Amphioxus, blastula, 220, 330, 331 ; 

 cleavage (radial), 235; fertiliza- 

 tion, 175; gastrulation, 333, ff., 

 335 ; notogenesis and mesoderm 

 formation, 337, 338; oocyte, 90; 

 spawning time, 103 



Amphitrite, ovary, diagram, 110 ; 

 spawning season, 103 



Amphiuma, spermatogenesis, 124; 

 spermatozoon, 99 



amplexus, 105 



Anamnia, 351 



anaphase, 53 



Anasa, chromosomes, 68 ; - - in 

 relation to sex, 307, ff.; spermato- 

 genesis, 308 



Andrews, 149 



animal pole, of ovum, 92 



anisogamy, 192, 196, ff.; facultative, 

 196, 197 



annulus, of spermatozoon, 100 



Apus, parthenogenesis, 203 



Arbacia, egg structure. 275, 276 



Arcella, plastogamy, 190 



archenteron, 334 



archoplasm, 38 



Argonaut a, micropyle, 96 



Aristotle, 1 



armadillo, multiple embryos, 315 



Artemia, maturation, 158 



Ascaris, cell lineage, 253, 255; 

 chromatin elimination during 

 early cleavage, 65; chromosomal 



continuity, 72, 74 ; variation 



(numerical), 66, 67; chromosome 

 groups during cleavage, 223; 

 cleavage, 254, 257; fertilization, 

 182; fused ova, 282; "giant" 

 polar bodies, 148, 149; idiochro- 

 mosomes, 311; primordial germ 

 cells, 112; segregation of germ, 

 133; spermatozoon, 99; tetrad 



formation, in oogenesis, 145 ; 



in spermatogenesis, 137 



asexual reproduction, 12 



aster, 39, 49 



Asterias, chromosomes from chro- 

 matin reservoir (nucleolus), 71; 

 development of parts of gastrula, 

 283 



Astropecten, maturation in partho- 

 genesis, 159 



attraction cone, 168; sphere, 39 



autogamy, 191 



autonomy of male and female chro- 

 mosome groups, 223 



axial filament, of spermatozoon, 98 



von Baer, 91, 355 



Balfour, 93; Law of Cleavage, 



230 



Baltzer, 75, 172, 303, 304, 311, 314 

 basal cells, 121 

 Bataillon, 303 

 bee, relation of sex to fertilization, 



315 

 Begonia, reproduction from cuttings, 



165 



van Beneden, 41, 65, 66, 80, 91, 131 

 Bernstein, 210 

 Beroe, cleavage (disymmetrical), 238 



367 



