SUBJECT INDEX 



215 



Sea urchin, potencies of 



blastomeres 45 

 , structure of cytoplasm 



33, 34 

 Segmentation nuclei 5 

 Segments 161, 162, 165, 166, 



169 

 Segregation 44 

 Self-differentiation 108, 109 

 Senility 2 

 Sense organs 156 

 Sensory nerves 174 



— neurones 156 

 Serological methods 135 

 Skeleton 172, 173, 175, 176, 



181 

 Skin 174, 176, 181 

 Snail 17, 62, 99 

 Sodium 15, 19, 46, 47 

 Somatoblasts 51, 52, 53, 54, 



56, 194 

 Somites 98, 100, 103, 111 et 



seq., 120 et seq., 126 

 Specificity in induction 



145 et seq. 

 Sperm 1, 4, 5, 7 et seq., 41, 195 

 Spermatid 8 

 Spermatocyte 8 

 Spermatozoon 7 et seq. 

 Sphaerechinus V6, 78 

 Spinal cord 115, 116, 146, 156 



— ganglion 156 



Spindle 8, 10, 16, 22, 25, 52, 72 



Sponges 99 



Spongioplasm 33, 195 



Starfish 9, 10 



— , activation 19, 21 



— , fertilisation 12 



— , maturation divisions 9 



Sterols 118 



Stimulation, local 144, 164, 175 



bcomodaeum 94, 195 



Stratification 31, 48 



Strongylocentrotus 13 



Sub-fields 149 



Substances, determining 5, 6, 



50 et seq., 91, 182 

 — , fertilisation 11 



— , gene 88, 89 



— , inducing 117, 145 



— , organ-forming 50, 60 



Suckers 139 



Sulphydryl compounds 34, 65, 



107, 118, 119 

 Superficial cleavage 70 

 Symmetry, bilateral 4, 39 et 



seq., 63, 91, 92, 94, 95, 134, 



182, 189 

 — , determination of 41 



— of auditory organs 137 



— of limbs 142 et seq. 

 Syncytium 83, 195 

 Synkarion 64, 195 

 Synthesis, ribonucleic acid 79 

 — , protein 34, 47, 65 



Tail-bud 113, 151, 152 



— , regeneration 172 et seq. 



Taste-buds 157 



Teeth 139 



Teloblasts 53, 195 



Temperature, influence of 10, 



20, 53, 77, 84, 146, 155, 163, 



164, 168, 171 

 Tendencies 101, 105, 144, 147 

 — , differentiation 108 

 Tendons 158 

 Tension 158 

 Tentacles 167 

 ,,Territoire de regeneration" 



175 

 Testis 8, 195 

 Tetraster 72, 73, 195 

 Thoracic segments 165, 166, 



168 

 Threshold 145 

 Tissue culture 154, 158 



— differentiation 150, 154, 182 

 Toad 22, 116 



Topc^enesis 2, 5, 6, 91 et seq., 

 115, 144, 182, 195 



Trabeculae 158 



Transplantation 80, 81, 85, 86, 

 87, 88, 107, 108, 109, 128 et 

 seq., 152, 155, 166, 167, 169, 

 170, 173, 175 et seq., 195 



