INDEX 323 



Theory, current, of the origin of species 213 



definition of 25 



Einstein's, of light-quanta 287, 298, 300 



of relativity 29, 75, 291 



Gaskell's, of life — see Life, the Gaskell theory of 



Theory of descent 199, 202 



bases of the 208, 209 



current 242, 244 



difficulties of the 203-213 



rejection of the 243-245 



Theory of life, what is demanded of a 49 



proof of a 26, 36 



quantum 87, 95, 99, 120, 298-300 



Thiele, T. U 23 



Thomson, Sir Joseph John 30, 104, 291 



Thorpe, J. F 89 



Thought, revolutions of 73, 74 



Tigerstedt, Robert 57, 289 



Townsend, John S 30 



Transmutation of elements 85, 86 



of species 245, 246 



Traube, Moritz 248 



Tropism 302 



Tropisms 251 



Tyndall, John 79 



effect 69, 302 



Uhlenhuth 58, 200 



Ultimate units 104 



Ultra-violet rays 302 



Unity of interpretation 256-258 



Universe, extent of the 80 



Uranium 82 



Valence electrons 303 



Valency 89, 295 



Van't Hoff factor i 303 



Variation 199, 208, 209-211, 229, 239 



Vaulx, R. de la 216 



Veraguth, Otto 57 



Verworn, Max 174 



Vinci, Leonardo da 31 



Vries, Hugo de 59, 229 



