INDEX 



577 



Senses of crayfish, 167 



Senses of fishes, 258 



Senso, from toadskins, 301 



Sensory nerves, 466 



Serpula, 104, 118 



Sertularia, "air-plant," 69 



Sesamoid bones, 426 



Setae, 106 



Seventeen year locust, 184 



Sex determination, 531 



Sex determining chromosome, 533 



Sex in Cladocera, 170 



Sex-linked characters, 535 



Sexual dimorphism, Triton, 267 



Sharks, 225 



Sharks of various types, 226 



Shark suckers, 250 



Sharp-shinned hawk, 345 



Sheep brain, ventral view, 468 



Sheep, 494 



Shelford, herring sensitivity, 260 



Short-nosed sturgeon, 241 



Short-tailed shrew, 377 



Shrews, 377 



Shrike, 353 



Shrimp, 175 



ShuU, 123 



Sidewinder or horned rattler, 325 



Significance of the Darwinian theory, 517 



Siliceous sponges, 47 



Silicon, 438 



Silk- worm moth, 187 



Singing earthworms, 115 



Siphonophora, 60, 61 



Sirenia, 409 



Sirenidae, 268 



Skate, 227 



Skate sucker, 118 



Skeleton of birds, 357-358 



Skeleton of Cistudo, 306 



Skeleton of garden toad, 292 



Skeleton, of gorilla, 415 



Skin, 427 



Skinks, 312 



Skin of fishes, 253 



Skull of the cat, 466 



Skunk, 387 



Slave making ants, 197, 484 



Sleeping sickness, 29 



Slime tube, earthworm, 113 



Sloths, 397 



Smallest adult snake, 323 



Smallest lizard, 312 



Small intestine, 430-359-360 



Smell and taste of crayfish, 167 



Smilodon, 380 



Smith, H., 236 



Smith, P. E., 448 



Smoky shrew, 378 



Smooth muscle, 426 



Snake tongue, 326 



Snapping turtle, 304 



Social life of animals, 482-489 



Societies, 485 



Sodium, 438 



Soft shell clam, 149 



Soft-shelled turtle, 305 



Solitary wasps, 197 



Somatic cells, 423 



Somatic sensory, 466 



Somatoplasm, 499 



Sound producing organs of drum-fish, 253 



Sound production, fishes, 253 



South American lung-fish, 252 



South American tapir, 400 



Spade-foot toad, 270 



Spanish mackerel, 251 



Sparrow, 353 



Sparrow hawks, 345 



Spectacled cobra, 317 



Speed of flight, 368 



Speidel, 479 



Spermaries, 55 



Spermatheca, 184 



Spermatogenesis, 503 



Spermatogonia, 500 



Spermatophores, earthworm, 113 



Sperm whales, 410 



Spicules, 47, 49. 51. 5^ 



Spider crab, 176 



Spider monkey, 413 



Spinal cord, 472 



Spinal nerves, 467 



Spiny ant-eater, 373, 374 



Spiracles, 183 



Spiral valve, 255 



/^' 



