/ N D EX. 



XXXlll 



Schelling, theory of life, i. 77. 



Schleiden, sources of nutriment of 

 plants, i. 136. 



Schultze, on Panspermism, i. 262. 



Schwann, on origin of cells, i. 144 ; 

 on Panspermism, i. 262 ; method 

 of experimentation with calcined 

 air, i. 337. 



Scolecida, modes of origin of repre- 

 sentatives of, ii. 539. 



Seguin, M., on convertibility of 

 forces, i. 9. 



Silicates, solutions of, containing 

 Fungi, xi-xiii ; spiral fibres, xiv ; 

 bodies resembling Sarcina, xiv. 



Silicon, as a possible substitute for 

 carbon in living matter, x. 



Small-pox, views on, cxxvii ; origin 

 of, cxliv ; contagiousness of, cxlix. 



Snake-poisoning, cxxviii, cxxx. 



Snow-flakes, ii. 280. 



Solution, nature of process, ii. 44. 



Spallanzani, l'Abb6, on Pansperm- 

 ism, i. 259. 



Species, meaning of term, ii. 547 ; 

 mutability of, ii. 548 ; nothing 

 corresponding to, amongst lower 

 forms, ii. 568 ; nature of, ii. 569 ; 

 influenced by change in external 

 conditions, ii. 577-582 ; by use 

 and disuse, ii. 577; to what ex- 

 tent influenced by natural selec- 

 tion, ii. 578 ; Darwin on influence 

 of new external conditions upon, 

 ii. 591 ; variation of, ii. 598 ; fre- 

 quency of spontaneous variation in 

 unknown, ii. 599 ; modes in which 

 transmutations are brought about, 

 ii. 600 ; Mr. Darwin's views con- 

 cerning, ii. 601-603. 



Spencer, Mr. Herbert, on converti- 

 bility of forces, i. 13 ; on meaning 

 of persistence force, i. 14 ; corre- 

 lation of vital and physical forces, 

 i. 22 ; consciousness, i. 45 ; mor- 

 phological development, i. 52 ; 

 characteristics of living things, i. 

 74 ; elements of organizable mat- 

 ter, i. 84; instability of protein 

 compounds, i. 86 ; original evolu- 



tion of life, i. 92 ; artificial evolu- 

 tion of organic matter, i. 94; oper- 

 ation of physical forces upon living 

 tissues, i. 98 ; evolution of living 

 matter, i. 163 ; organic polarity, 

 ii. 23 ; physiological units, ii. 23, 

 90, 98 ; law of heredity, ii. 94, 

 97; nature of evolution, ii. 120; 

 two meanings of natural selection, 

 ii- 573 ; denies existence of internal 

 organizing tendencies, ii. 585 ; 

 cause of organization, ii. 587 ; his 

 explanation of existence of undif- 

 ferentiated organisms in present 

 day, ii. 587-589; physiological 

 units, ii. 603 ; limits to variability 

 of species, ii. 610. 



Spermatozoa, development of, i. 213. 



Sperm-cells, ii. 96. 



Spiral fibres, v ; where found, viii ; 

 in association with mycelium, 

 viii ; in silicated solution, xiv. 



Spirillum, i. 277, ii. 139. 



Spirogyra, transformations in, ii. 



3 8 7-393. 

 Spontaneous Generation, reason for 



rejecting term, i. 244 ; views of 



ancient writers concerning, i. 253; 



other views concerning, i. 255- 



263 ; two processes included under 



term, ii. 172. 

 Spores, mode of formation of, in 



CEdogonium, i. I77 i n Zygne- 



meacese, i. 1 79 ; in Fungi and 



Lichens, i. 183 ; in Peziza, i. 184; 



in Hydrodictyon, i. 186 ; Physcia, 



i. 186. 



Starch-grains, production of, ii. 65. 

 Steenstrup, on alternate generation, 



ii. 565. 

 Stein, views concerning Acinetre 



and Vorticellse, xciv-xcvii. 

 Survival of the fittest, ii. 575. 

 Syphilis, cxxxii. 



Tables relating to : (i) origin of 

 living things, i. 252 ; (2) modes of 

 origin of independent living units, 

 ii. 545 ; (3) modes of reproduction 



