NDEX 



717 



Shark, 289, 522 



Shell, 253, 255, 256, 257, 320 



gland, 172, 173 

 Shrimp, 204 

 Siamese twins, 572, 573 

 Sigmoid flexure, 466 

 Silurian (period), 287, 625 

 Simpson, G. G., 658 

 Sinanthroptis, 355, 356 

 Sinus, 212, 213, 254 



gland, 220 



node, 500 



venosus, 313 

 Siphonaptera, 221 

 Siphons, 256, 283 

 Sirenia, 345 

 Skeleton, 303, 305 



bird, 333 



frog, 303, 305, 306, 307 



man, 374-384 



rabbit, 375 

 Skin, 302, 365-373, 367 



receptors, 394 



color, 598 

 Skull, frog, 306 



man, 377, 378 

 Skunk, 635 

 Smell, 396 

 Snake, 326-331 



feeding, 330 

 Snail, land, 263 

 Social insects, 242, 243 

 Sociology, 16 

 Sol, 50 

 Solids, 24 

 Solute, 47 

 Solvent, 47 

 Soma cells, 555 

 Somatotrophin, 447 

 Somite, 564, 565 

 Sound perception, 407 

 Space, 22 

 Spallanzani, 458 

 Spectrum, 91 

 Species, 106, 107 



number of, 628 

 Speech, 424 



Spemann, Hans, 572, 573 

 Sperm, 83, 165 

 Sperm duct. See Vas deferens 

 Sperm sac, 317, 318 

 Spermatheca, 234 

 Spermatocyte, primary, 556, 557 



secondary, 556, 557 

 Spermatogonium, 556, 557 

 Spermatophores, 215 

 Spermist, 561 

 Spinal nerves, 309, 312 

 Sphenodon, 324, 325, 668 

 Sphincter, anal, 457 



cardiac, 457 



ileocaecal, 457, 465 



pyloric, 312, 457 

 Spicules, 138, 139 



Spiders, 246-250 



Spinal column, 376, 379, 380 



Spindle, 552, 553, 554 



cells, 316 

 Spiracle, 226, 227 

 Spirobolus. See Millipede 

 Spirostomum, 134, 135 

 Spleen, 311 

 Splenic artery, 314 



vein, 315 

 Spirotricha, 134 

 Sponges, 136, 137, 374, 375 

 Spongin, 140 

 Spongocoel, 139 

 Sporocyst, 167, 169 

 Sporozoa, 130-134 

 Sporozoites, 131, 132 

 Spur, 230, 231 

 Squash bug. See Anasa 

 Squid, 265, 266 



Stagmomantis Carolina. See Praying mantis 

 Stapes, 405 



Starch, 41, 46, 455, 464 

 Starfish, 268, 269-274, 282 



embryology, 563 

 Stationary phase of growth, 578 

 Statocysts, 153, 218 

 Statolith, 218 

 Steapsin, 463, 464 

 Stentor, 133, 135 

 Sternomastoid, 386 

 Sternum, 207, 303, 304, 376 

 Stigma, 121, 122 

 Sting, 229, 232 

 Stirrup. See Stapes 

 St. Martin, Alexis, 459 

 Stomach, 211, 212, 225, 233, 256, 258, 269, 272, 



311, 312, 453, 457 

 Stone canal, 269, 271 



Stratum germinativum, 367, 369, 370, 371 

 Stijlonichia, 133, 135 

 Subclavian artery, 314 



vein, 315 

 Subesophageal ganglion, 219, 226, 227 

 Sublingual gland, 455 

 Submaxillary gland, 455 

 Suckers, 167 

 Sucrase, 464 

 Sucrose, 40, 233, 464 

 Suctoria, 133, 135 



Supra-branchial (epibranchial) chamber, 257, 258 

 Surface phenomena, 23 

 Surface tension, 24 

 Survival of the Fittest, 652 

 Suspensions, 47 



Suspensory ligament, 398, 400, 401 

 Sustentative tissue, 71, 72 

 Sutton, W. S., 585 

 Suture, 378 



Swallowing, 56, 456, 457 

 Swim bladder. See Air bladder 

 Swimmeret, 208, 209, 210 

 Sijcon, 137, 140 

 Symbiosis, 95, 96, 97 



