Sondera heterophylla, 284

Sorby, Mr., on colouring matter of Drosera, 5

Spectroscope, its power compared with that of Drosera, 170

Starch, action of, on Drosera, 78, 126

Stein, on Aldrovanda, 321

Strontium, salts of, action on Drosera, 183

Strychnine, salts of, action on Drosera, 199

Sugar, solution of, action of, on Drosera, 78 —, —, inducing aggregation in Drosera, 51

Sulphuric ether, action on Drosera, 219 —, — on Dionaea, 304

Syntonin, its action on Drosera, 102