INDEX 



729 



Smilisca, 519. 



Snail, 253-257. 



Snakes, 527, 536, 538-539, 557^9; 



Congo, 514; horsehair, 179. 

 Snipe, 590, 607. 

 Sole, 469. 

 Solen, 262. 

 Solenodontida, 650. 

 Solifugce, 382. 

 Somatic, cells, 46, 47, 73; mesoderm, 



507. 

 Somite, 90. 

 Songs of birds, 621. 

 Sorex, 642, 649, 650 ; Soricidm, 649. 

 Sparrow, 593, 615. 

 Spatangus, 190. 

 Species, 22, 23. 

 Spelerpes, 511, 517. 

 Spermatheca, 226, 227 (see reproductive 



system) . 

 Spermatid, 81. 

 Spermatocytes, 81. 

 Spermatogenesis, 81-82. 

 Spermatogonia, 81. 

 Spermatozoa, 47, 75, 81. 

 Sphcerodactylus, 537, 552. 

 Sphcerophyra, 65. 

 Sphargis, 544. 

 Sphegida, 364, 367. 

 Sphenethmoid, 493, 494. 

 Spheniscus, 589; Spheniscijormes, 589, 



598. 

 Sphenodon, 536, 546, 695. 

 Sphingida, 352; Sphinx, 335. 

 Sphyranura, 161. 

 Sphyrna, 429. 



Spicules, of sponges, 93, 95, 99, 191. 

 Spiders, 24, 37i~377- 

 Spilogale, 655. 

 Spinal cord, 408, 503-504 (see nervous 



system). 

 Spinal nerves, 503, 504 (see nervous 



system). 

 Spines, of echinoderms, 190, 201, 292; 



haemal, 436; of perch, 435. 

 Spinneret, 373, 376. 

 Spiracle, insects, 319, 320; Squalus, 424; 



tadpole, 510. 

 Spiral valve, 418, 423, 425. 

 Spireme, 15. 

 Spirobolus, 310. 

 Spirorbis, 236. 



Spirostomum, 63. 



Spittle insects, 346. 



Splanchnic mesoderm, 507. 



Spleen, 451; frog, 492 ; perch, 438; ver- 

 tebrates, 401, 402. 



Sponges, 23, 92-107. 



Spongilla, 98, 98, 100. 



Spongin, 99, 101. 



Spongoblasts, 100. 



Spontaneous generation, 12. 



Spores, 48, 49. 



Sporoblast, 49, 50. 



Sporocyst, 159, 160. 



Sporozoa, 27, 48^5 



Sporozoites, 49, 50. 



Sporulation, 3$. 



Springtails, 337, 338. 



Squali, 428. 



Squalus, 422-428. 



Squamata, 527, 536, 550-569, 694, 695 



Squamosal, 493, 494. 



Squid, 264-267. 



Squilla, 298, 299, 301. 



Squirrel, 643, 658, 659. 



SlaphylinidcB, 361. 



Starfish, 24, 189, 190-199. 



Starling, 591. 



Statocyst, 286 (see sense organs). 



Statolith, 286 (see sense organs). 



Staurovieduse, 132, 133. 



Staurotypus, 535. 



Stegocephalia, 525, 526, 694, 695. 



Stegomyia, 356. 



Stegosaurus, 572, 573. 



Slenopus, 297. 



Slenlor, 64. 



Stercoral pocket, 373, 374. 



Stereolepis, 466. 



Sternothoerus, 535. 



Sternum, 276, 372, 495, 496 (see skele 

 ton). 



Stickleback, 444, 464. 



Stigma, 42, 43. 



Stigmata, 378, 379. 



Stilt, 607. 



Sting, 317. 



Stolonifera, 139, 140. 



Stomach, cardiac, 480; pyloric, 481 (see 

 digestive system). 



Stomato-gastric ganglion, 321. 



Slomatopoda, 297, 298. 



Stomias, 473. 



