INDEX 383 



Growth 



law of, in the organism, 172; by accretion, 169; by ecdysis, 276; 

 geometrical, 169 ; physical, 167 ; of crystals, 167 ; and differentiation, 

 170 ; variability of, 172. 



Haeckel, the Gastrea-Theorie, 177, 254. 

 Harmonic analysis, II. 

 Harvey, and the circulation of the blood, 

 Heat, flow of, 117 ; 



production of, in physical changes, 114. 

 Heliotropism, 144. 

 Heredity, 181. 

 Hertzian waves, 355. 

 Homoiothermic animals, 67. 

 Hormones, 225. 



Human activity, tends to arrest dissipation of energy, 312. 

 Huxley, 84 ; 



and mechanistic biology, 127 ; and the physical basis of life, 113 ; and 



mechanism, 106 ; and universal mathematics, 215. 

 Hybrids, Mendelian, 196; 



infertility of, 195 ; between Linnean species, 194. 

 Hydra, regeneration of, 162. 



Idants, 183. 



Idealism founded on pure reasoning, 45 ; 



of Berkeley, 45. 

 Ids, 183. 

 Immunity, 35. 

 Individual, 162 ; 



definition of, 167. 

 Individuality, orders of, 163 ; 



physical concept of, 165 ; morphologically an artificial concept, 166 ; 



in societies, 171. 

 Inertia, 354. 



Infinity, a definition of, 342. 

 Inorganic happening abolishes diversity, 310. 

 Instinct, a problem for naturalists, 283 ; 



an inheritable adaptation of behaviour, 287. 

 Instinct and intelligence, 283 ; 



distinction not absolute, 294 ; may coexist, 306. 

 Instinct and functioning, 286. 

 Instinctive actions not necessarily unconscious, 283 ; 



not learned, 286 ; not necessarily perfect, 284 ; effective from the first, 



285 ; capable of improvement, 285. 

 Intelligent actions, non-inheritable adaptations of behaviour, 287 ; 



involve deliberation, 50, 287 ; involve conscious relations with the 



environment, 288 ; involve use of tools, 284. 



