500 



INDEX 



arm-field, 229 



Triton, 362, 363 

 armadillo, twinning, 329 

 Arthropods, gradients, 320 



limb-regeneration, 303 



regeneration, 360 

 Ascaris, chromatin-diminution, 398, 

 399, 400 



cleavage, 84 



giant embryo, 10 1 

 Ascidians, blastomeres isolated, 96, 



99 



cleavage, 83 



differential susceptibility, 294 



egg, viscosity, 108 



germ-layers, 153 



gradient-system, 437 



organ-forming substances, 118, 216 



polarity, 67 



precocious chemo-differentiation, 

 123 



prelocalisation, 118, 125 



regeneration, 198 

 Ascidiella, partial larvae, 124 

 Asterina, asymmetry, 81 



dorso-ventral axis, 69 

 asymmetry, 70 f. 



Amphioxus , 70, 79, 80 



gradient, 77, 81, 265, 361 



limb, 358 



Lifnnea, heredity of asymmetry, 411 



normal, 79 



ovaries, 264 



reduplicated limbs, 224 

 atavism, 372 

 atropine, effect of, 344 

 auditory capsule, 175 

 autonomic nervous system, and limb- 

 regeneration, 420 

 autonomy of apical region, 283 

 axial gradients, 278, 331, 372, 378, 379 

 axial structures, 135 

 axiation, 60, 65 

 axis, egg, 13 



axolotl (see also A7nblystoma) , adult 

 characters, 403 



balancer, 176 



chimaeras, 405, 406 



cleavage, 132 



dorsal fin, 423, 424 



hind-limb field, 230 



limb-differentiation, 419 



regeneration-buds, 405, 406 

 axons, 378 



Bahnung, 136 

 balance, sense of, 209 

 balancer, 31, 177, 192 



mosaic development, 199 



Triton, axolotl, 176 

 balancer-field, 236 

 balancer-induction, Ajiihlystoma, 236 



Rana, 236 

 Bateson's rule, 224 

 Beroe, cleavage, 105 



organ-forming substances, 108, 117 



viscosity, 126 

 biaxial regeneration, 296, 299 

 Bidder's organ, 257, 258, 260 

 bilateral symmetry, 15, 36 f., 53, 56, 



67 f., 79, 119, 126, 139 

 bilaterality, Atnphioxus,' 80 



frog's egg, 14 

 biological integration, 57 

 biological order, 1 1 

 birds, double monsters, 329 



extra-embryonic blastoderm, 327 



feather-growth, 369 



gonad-asymmetry, 362 



organiser, 159 f., 162 



plasticity, 100 



polarity, 63 

 bladder, differentiation, 434 

 blastocoel, 15, 17 

 blastoderm, 327, 331 



bird, 159 f. 



experimental production in frog, 40 

 blastomeres, 15, 33, 39 



Amphibia, 98 



Amphioxus, 100 



Ascidians, 96 



Echinoderms, 98 



Hydrozoa, 96 



isolated, 96 f. 



Nemertines, 98 

 blastopore, 16, 18, 27, 29, 41, 95 

 blastopore-lip, amphibian, 12 

 blastopore-rim, amphibian, 17 

 blastula, 13, 40 



blood, mosaic development, 138 

 blood-islands, chick, 205 

 blood-vessels, differentiation, 174, 434 

 blow-fly, explantation of imaginal 



discs, 174 

 Bombinator , blastula regulation, 94 



eye, self-differentiation, 48 



gill-field, 233 



heart, 203 



heart-field, 233, 234, 235 



