284 



INDEX 



Rat, size of litters of, 109 



Eeduction of heterozygous individ- 

 uals and allelomorphic pairs, 90 



Remick, 92 



Reproduction, among animals and 

 plants, 20 

 asexual, 17, 21, 22, 30, 78 

 sexual, 17, 20^., 26, 201, 205 

 sexual, origin of, 2()ff. 



Retina, pigmentary degeneration of, 

 231 



Rhopalura, 26 



Rice, 114 



Ripley, 257 



Ritzema-Bos, 101^., 188 



Roberts, 153 



Robbins, 92 



Roman Empire, 259 



Romans, 259 



Rome, 251 



Rommel, 110 



Rosacece, 32 



Rotifer, 158, 170, 202 



SaccuUna, 23 



Sageret, 141, 144, 15G, 192 



Sax, 157 



Saxons, 258, 2G0 



Scandinavians, 257 



Schizopliytes, 26 



School for mothers, 227 



Scotch, 259f. 



Scotland, 257, 260 



Sex, determination of, 43^. 



Sexual dimorphism, 26 



Self-fertilization as means of obtain- 

 ing homozygosity, 97 



Self- sterility, 25, 33 



Sex-linked characters, 47^. 

 inheritance of, 48/". 



Sex, origin of, 201 



Sex ratio, 106 



Shamel, 119 



Sheep, 210^. 



Shull, A. F., 112/=., 158, 169 



Shull, G. IL, 118f., 168/. 



Silkworms, 158 

 Spain, 257/. 

 Spaniard, 262 

 Spermatogenesis, 37 

 Spermatozoon, entrance of, through 



membrane of egg, 42 

 Spliwrocarpus, 45 



Donnellii, 45 



texanus, 45 

 Spirogyra, 27 

 Sponges, 21^. 

 Spores, 29 

 Sporophyte, 29 

 Squashes, 221 

 Sterility, 188^. 

 Stevenson, 233 

 Stone Age, 258 

 Strasburger, 45 

 Sturtevant, 184 

 Htylonychia pustulata, 78 

 Swine, 210/., 213 

 Synapsis, 37 

 Syndactyly, 230 



Talmud, Hebraic, 14 

 Tapeworm, 23/. 

 Tobacco, 114, 148, 156 

 corolla length of, 70 

 Tomatoes, 114, 148, 221 

 Toyama, 158 

 Trochelminthes, 21/., 202 

 Tropa^olum, 144 

 Tunicates, 23 

 Turanian, 259; race, 258 

 Turbellarians, 23 

 Tuttle, 235 



Ulothrix, 26, 28 



Unit of heredity, 77 



United Kingdom, 257 



United States, 253^., 260, 262, 264 



Ustilago maydis, 118 



Venable, 235 

 Verhascum, 142, 144 



