INDEX 



319 



Sea anemones, 68. 



Sea elephant, 38. 



Seals, 38, 39, 40, 209. 



Selection, natural, doctrine of, 116, 

 117, 118; struggle for existence, 

 124, 125 ; simply trial and error, 

 131, 136, artificial, 130, 137, 138; 

 laws of, in mental phenomena, 203. 



Sequence, physiological, in training 

 animals, 209 ; 210. 



Series, sedimentary, 84, 90, 92 ; 

 crystalline or plutonic, 85 ; Azoic 

 or ArcheBan, age of, 92. 



Shale, 89. 



Shark, common, most fundamental 

 form, 46 ; embryo of, hammerhead ; 

 embryos of, 66. 



Sheep, 157. 



Simiidae, 160, 163. 



Skate, embryos of, 66. 



Snails, 45 ; shells of, 95 ; land snails, 

 103 ; Hawaiian and Polynesian, 

 104. 



Society Islands, 103. 



Solar system, origin of, 84. 



Solomon Islands, 103. 



Species, origin of human, 153. 



Spencer, Herbert, 8. 



Squirrels, evolved from terrestrial 

 rodents, 14 ; 41 ; flying, true ro- 

 dents, 41. 



Starch, 24. 



Stephenson, 10. 



Strata, 88, 89 ; arranged according 

 to ages, 89 ; 90 ; time of formation, 

 92. 



Struggle for existence, 124; intra- 

 specific, 125 ; three div-isions of, 

 126-129 ; 139, 174, 175. 



Substances, inorganic, 29. 



Sugar, 23, 24. 



Survival of the fittest, 129. 



Systems, respiratory, excretory, cir- 

 culatory, 17 ; organic, reproduc- 

 tive, 18 ; nervous, 256, 257 ; 

 blood-vascular, respiratory and 

 excretory, 257 ; ethical, 286 ; reli- 

 gious, 288. 



Tadpole, 58, 59, 60 ; larva, 64. 

 Tapeworm, a relative of simple 

 worms, 50 ; 123. 



Tapir, 41 ; MiTritherium, 97. 

 Thorndike, 209 ; heredity of mental 



qualities, 232. 

 Tidal waves, 85. 

 Tigers, 101. 

 Tirawa, 301. 

 Tissue-cells, 28. 

 Torga, 183. 

 Tortoise, soft shelled, of the Miaais- 



sippi, 45. 

 Tower, 148. 



Transformation, natural, 170. 

 Trilx-s, 32. 



TuV>erculoHi3, bacillus of, 127. 

 Turtles, evolution of, 45. 



Ungulates, 65. 



Uniformitarianism, Lyell's doctrine, 



80. 

 Urea, 29. 

 Ussher, Archbishop, 178. 



Variation, 110; cauaes of, 111; 

 among individuals, 112, 113; fact 

 of difi'ercnce, phenomenon of, 114; 

 115, 118, 119, 121. 129 ; congenital, 

 138; human, 174; racial, 177; 

 laws of, in mental phenomena, 203 ; 

 232. 



Vertebrata, 43. 



Vertebrates, backboned animals, 

 fishes the lowest order of, 46; 

 principles of relationship, families, 

 tribes, 47 ; 53-59 ; great classes 

 originate together, 64 ; more com- 

 plicated, 68 ; skeleton remains of, 

 succeed invertebrates, 92 ; testi- 

 mony of the rocks, 93 ; largest, 94 

 appearance of great classes of, 94 

 95; classes that make up, 156 

 lower, arrangement of organs, 201 

 nervous system of, 256, 257. 



Volcanoes, 88. 



Volvox, 252, 254, 259, 265. 



Von Baer, law of recapitulation, 71. 



VorticeUa, 251, 252, 265. 



Wagner, 100. 



Wallace, Alfred Rusael, 117. 100. 

 Walruses, 38. 



Wasps, ground. 207; organizatioDB, 

 of digger, 260 ; 201. 



