118 



Mutations and Evolution. 



Simocephalus vetulus 

 Singleness, inheritance of, 

 Siphonogamy ... 



Small 



Snapping turtles 



Snell 



Society Islands... 



Sollas, Miss 



Sowerby 



Species and varieties 



Species cell 



Spiraea ... 



Spiranthes, pair of specres 



Sponges, evolution in, 



Sporogenesis, 



relation to sporophyte, 

 Staphylea pinnata, 



chromos 

 Stebbing 

 Sterns 



Stocks, see Matthiola. 

 Stomps 



Stone 



Streptopus, pairs of species, 55 



Sturtevant 



Sumner 



Sunflower, see Helianthus. 



Sutton, Miss ... 



Tachygenesis ... 

 Tadpoles, adaptation in, 

 fed on thymns 



Tahiti ; 



Tennessee 



Tephrosia, melanism in, 



Tetraploidy 



Thalictrum, double 

 Thistleton-Dyer 



