480 



INDEX. 



Skin senses, 350 



Skeletal system, 66 in protozoa, 154; 

 porifera, 159, 161 ; coelenterates, 

 174; echinoderms, 202, 205; annu- 

 lates, 223 ; mollusks, 242 ; arthro- 

 pods. 276 ; vertebrates, 324 ; fishes, 

 360 ; amphibia, 373 ; reptiles, 382 ; 

 birds, 399 ; mammals, 432 



Skull, 359 



Sloths, 441 



Slugs, 254 



Smell, 74, 350 



Smelt, 366 



Snails, 237, 254, 256 



Snakes, 389 



Snipe, 412 



Snowy grouper, 370 



Social instincts, 113, 287, 449 



Somite (see segment) 



Sow-bug, 265, 289 



Sparrows, 422 



Species, 102-103 



Special senses, 74 



Spermatozoon, 29 



Sphincter, 333 



Spider, 266, 304, 305 



Spinal cord, 348 



Spinal nerves, 348 



Spinous process, 325 



Spinus, 422 



Spiracle, 268 



Spirastomum, 148 



Sponges, 140, 156 (see porifera) 



Spontaneous generation, 153 



Sporocyst, 189, 190 



Sporozoa, 154 



Squamous epithelium, 42 



Squid, 239, 257 



Starfish, 200, 205, 213 



S tent or, 148 



Sternum, 262, 327, 328 



Stigmata, 278 



Stimulus, 12 



Stolon, 176 



Stomodaeum, 61, 277, 330 



Stomach, 331, 332 



Stork, 412 



Streptoneura, 255 



Striate muscle, 53 



Strobila, 184, 191 



Struggle for existence, 95 



Struthio, 407 



Sturgeon, 368 



Sunfish, 369 



Supplementary studies protozoa, 155 ; 

 porifera, 164; ccelenterata, 181 ; 

 unsegmented worms, 198, 199; 

 echinoderms, 214 ; annulata, 233 ; 



mollusca, 259; arthropods, 271,. 306; 



fishes, 371 ; reptiles, 392 ; birds, 424 ; 



mammals, 449 



Supportive tissue (see connective) 

 Suture, 432 

 Swallow, 422 



Swallow-tailed butterfly, 301 

 Sweat glands, 323, 324 

 Swifts, 422 

 Swine, 442 

 Symbiosis, 116 

 Symmetry, 84, 368 

 Sympathetic system, 349 

 Syrinx, 401 



Tacnia, 190, 191, 192, 199 

 Tail, 358 



Tape-worm (see Tcenia) 

 Tapir, 443 



Tarso-metatarsus, 400 

 Tarsus, 269 

 Teeth, 432 

 Teleostei, 369 

 Telophase, 23 

 Tent caterpillars, 300 

 Teredo, 253 

 Tergum, 262 

 Termites, 296 

 Testis, 69, 227 

 Tetrabranchiata, 257 

 Tetradecapoda, 289 

 Thread-worms, 193 

 Thrushes, 422, 423 

 Thysanuran, 294 

 Tibia, 269 

 Ticks, 306 

 Tiger, 443 



Tissues definition, 40 ; differentia- 

 tion, 37 ; classification, 41 

 Toad, 378 

 Tortoises, 388 

 Tortoise-shell, 382 

 Toucans, 419 

 Touch, 69 

 Trachea, 335 

 Tracheae, 63, 270 

 Transverse section, 83 

 Tree-toads, 379 

 Trematodes, 187 

 Trichina, 193 

 Trivium, 205 

 Trochanter, 269 

 Trochosphere, 228, 229, 250 

 Trophoblast, 437, 438 

 Tube-feet, 207 

 Tubifex, 232 

 Tunicates, 309 

 Turbellaria, 187, 188 



