INDEX 



487 



Silva, carmen, 167. 



Skate, egg case of barn door (illus.), 



339. 



Slime mold (illus.), 32. 

 Snails, distribution of land, of 



Hawaii, 123. 



Solenopsis fuga, nest of (illus.), 392. 

 Species, changing with space and 



time, 18; estimate of duration 



of, 302; number of, 14; onto- 



genetic, 114. 

 Species-forming, 117; by saltations, 



156; various theories of, 108. 

 Spencer, Herbert, 5, 196, 197, 198; 



definition of evolution, 5; theory 



of protoplasmic structure, 250. 

 Spermatogenesis of ascaris (illus.), 



264. 



Spermatozoa (illus.), 218. 

 Spermatozoan, development of 



(illus.), 266. 

 Spermatozoid, 261. 

 Sphcerechinus Echinus, hybrid larva 



of (illus.), 277; hybrid pluteus 



of (illus.), 280. 

 Sphcerechinus gramdaris, heating 



larva of (illus.), 279; lithium 



gastrula of (illus.), 279; lithium 



larva of (illus.), 278; normal 



larva of (illus.), 275. 

 Sphenodon, pineal eye of (illus.), 



175. 

 Spider, nest of trap door (illus.), 



346. 



Sponge, simple (illus.), 36. 

 Sports, 186; examples of race formed 



from, 161; species arising from, 



107. 



Sporulation, reproduction by, 215. 

 Squid (illus.), 40. 

 Stamens of willows, variation in 



(illus.), 160. 

 Stanford, Leland, 103. 

 Starfish, regeneration of (illus.), 



283; walking (illus.), 23. 

 Starks, E. C., 303. 

 Stentor cceruleus (illus.), 282; re- 



acting to light (illus.), 430; 



reproducing by fission (illus.), 



215. 

 Sticklebacks (illus.), 209; onto- 



gonetic variations in, 207. 

 Sting-ray (illus.), 333. 

 Structures, convergence of, 204; 



parallelisms in, 204. 

 Struggle for existence, 57, 60. 

 Struthio camelus (illus.), 45. 

 Sunfish, long-eared (illus.), 17. 

 Survival of the fittest, 62. 

 Swift, common (illus.), 18. 

 Swordfish, development of (illus.), 



239. 

 Symbiosis, 373; of plants and 



animals, 376. 



Syngamus trachealis (illus.), 223. 

 Systema Naturae, 14. 



Tcenia solium (illus.), 355. 



Tail of man, hology of, 179. 



Tailor bird, nest of (illus.), 444. 



Tapeworm (illus.), 355. 



Tarsal segments, variation in, cock- 

 roach (illus.), 149. 



Taxis, 282. 



Taylor, Bayard, 163. 



Teeth of man and orang-utan com- 

 pared (illus.), 454. 



Telegony, 166. 



Telophase defined, 256. 



Temperature in relation to animal 

 life, 38. 



Termitophily, 372. 



Termites, castes of (illus.), 395; 

 communal life of, 394. 



Terrifying appearances, 418. 



Thalessa (illus.), 361; (illus.), 362. 



Theory, transmutation, of Lamarck, 

 111. 



Timothy, heads of, improved by 

 selection (illus.), 91. 



Toad (illus.), 344; horned, pineal 

 eye of (illus.), 176; metamor- 

 phosis of (illus.), 237. 



Tobacco worm (illus.), 418. 



