INDEX 



721 



Sperm (Cont.) : 



funnel, 180 



whale, 480, 486 

 Spermatic vein, 337 

 Spermatid, 80, 576 

 Spermatocyte, 80, 115, 576 



primary, 80, 115, 576 



secondary, 80, 115, 576 

 Spermatogenesis, 80, 211, 563 

 Spermatogonia, 80, 115, 576, 583 

 Spermatozoa, 79, 80, 115 

 Sphecidae, 265 

 Sphenethmoid, 343, 344 

 Sphenisciformes, 461 

 Spheniscus, 461 

 Sphenodon, 325, 405, 412, 413, 



430 

 Sphenodontidae, 407 

 Sphenoid, 500, 502 

 Spherical symmetry, 88 

 Sphincters, 517 

 Sphingidae, 264 

 Sphinx moth, 256 

 Spicules, 94, 95, 98 



penial, 151 

 Spider, 198, 267-273 



circulatory system, 271 



digestive system, 270 



excretory system, 271 



external anatomy, 267 



internal anatomy, 269 



nervous system, 271 



physiology, 270 



reproduction, 271 



respiration, 271 

 Spider crab, 218 



monkey, 489, 490 

 Spinal accessory nerve, 353, 546 



cord, 350. 351, 353, 566 



nerves, 350, 351, 352, 353 



root, 546 

 Spindle, 25 

 Spine, fish, 381 



Hydra, 110 



sea urchin, 309 



starfish, 303, 307 

 Spineheaded worm, 160, 161 

 Spinneret, 269, 270, 272 

 Spiny anteater, 464, 481, 495 



dogfish shark, 368 

 Spiracle, 231, 233, 269, 358, 370 

 Spiral intestine, 358 



valve, 370, 371 

 Spirobolus, 111 

 Spirotricha, 64 

 Spirotrichonympha, 49, 639 

 Spittle insect, 264 

 Splanchnic mesoderm, 356, 565 

 Spleen, 330, 370, 529, 532 

 Splenic artery, 338 



vein, 338 

 Spondylomorum, 42, 561, 562 

 Sponge, 92-101, 98, 607 



commercial bath, 93 



Sponge (Cont.) : 



elephant's car, 93 



finger, 93 



freshwater, 93 



glass rope, 93 



origin and relations, 99 



Venus's flower basket, 93 

 {see I'orifera) 

 SpOTigia, 101 

 Spongilla, 99 

 Spongillidae, 99 

 Spongin, 98 

 Spongoblast, 98 

 Spongocoel, 93, 95 

 Spontaneous generation, 601, 602 



movements, 115 

 Spoonbills, 461 

 Spore, 51, 52 

 Sporocyst, 139, 140 

 Sporogony, 69 

 Sporozoa, 31, 50-53 



classification, 53 



origin, 52 

 Sporozoite, 51, 69 

 Spotted fever tick, 275 

 Spreading viper, 418 

 Spring peeper, 402 

 Springtails, 229, 260 

 Spur, 245 

 Squahda, 376 

 Squalus, 368. 369, 376 

 Squamata, 405, 407,430 

 Squamosal, 343, 344 

 Squamous epithelium, 84, 85 



stratified. 85 

 Squash bug, 264 

 Squid, 282, 283, 293 



eye. 295 



ink sac, 294 



internal structure, 294 

 Squirrel. 317, 325,485 



monkey, 489 

 Stag beetle, 264 



Stalk, Ilvdra, 103, 106, 112, 311 

 Stapes, 500, 549 

 Staphylinidae, 264 

 Starch, 519 



Starfish, 303-308, 306, 312, 313, 

 606 



digestive system, 305, 306 



excretion, 306 



life cycle, 308 



nervous system, 306 



regeneration, 308, 312 



reproduction, 308 



respiration, 306 



sense organs, 306 



skeleton, 303 



structure, 303, 307 



water vascular system, 305 

 Starlings, 462 

 Statoblast, 166, 167 

 Statocyst, 120, 130, 211, 288, 

 295 



Statolith, 211, 288 



Stegoccphali, 400 



StegosauTus, 426 



Stenostomum, 147 



StentOT, 64, 65 



Stercoral pocket, 269, 271 



Stereograms of chordate embrvo, 



565 

 Sternal artery, 202 

 Sternocleidomastoidcus, 506 

 Stemomastoid, 467 

 Sternothenis, 411 

 Sternum, 199, 233, 269, 345, 435, 



437, 501 

 Stickleback, 390, 395 

 Sting, 245 



ray, 374, 375 

 Stink bug, 229, 264 

 Stirrup, 549 

 Stomach, frog, 331, 332 



grasshopper, 235, 236 



Hydra, 103 



man, 515, 517 



reproductive and stalk region, 

 111 



rotifera, 164 

 Stomatogastric ganglion, 209 

 Stomodaeum, 130 

 Stone canal, 304, 309 



fly, 229, 260 

 Storks, 461 

 Strainer, 204 



Stratification, ecologic, 644 

 Stratified tissue, 84 



squamous, 85 

 Stratum compactuni, 328 



corneum, 328 



germinativum. 328 



spongiosum, 328 

 Streblomastix, 639 

 Strepsiptera, 229, 260, 264 

 Striated muscle, 86. 151, 235, 346 

 Striations, 173 

 Strigiformes, 433, 461 

 Striped cucumber beetle, 258 

 Strobila, 122 

 Strombus, 293, 301 

 Strongyloidea, 161 

 Strongylus, 154 



Struggle for existence, 610, 649 

 StTuthio, 461 



Struthioniformes, 433, 461 

 Sturgeon, 379, 394 

 Sturnidae, 462 

 Stylochus, 147 

 Stylonvchia, 64, 65 

 Stylopids. 260 

 Subclavian, artery, 336, 338, 532 



vein, 337, 338, 532 

 Subcutaneous tissue, 328, 329 

 Subdermal cavity, 96 

 Subendostylar coelom, 319 

 Subfamily, 8 

 Subgcnital pit, 122 



