836 



INDEX 



Siamese cat, 412 



Sieve plate. 655, 656, 657 



Sigh, 241 



Silicon. 174 



Silk glands, 624, 625 



Silurian sea bottom, 575 



Silverfish. 590, 595 



Sinanthropus, 772 



Sinuauricular node, 217, 218 



Sinus, frontal. 235, 270 



maxillary, 235 

 Sinus gland, 257 

 Sinus venosus, 699, 700, 701 

 Siphonaptera, 593 



Siphons, 636, 637, 638-640, 641, 647, 650 

 Skeleton, 135, 154 



bird, 738, 739 



fish, 672, 673 



frog, 693 



horse, 149 



human, 148, 150 



reptile, 716, 725 

 Skeleton content, 139 



functions, 135 



permanent, 137 



temporary, 137, 138 

 Skin, 126 



frog, 692 



functions, 133, 134 



human, 128,310 



sense organs. 31 1 



structure, 127 

 Skin muscles of horse, 164 

 Skull, 150, 153 

 Slug, 630, 631, 633, 643 



sea, 646 

 Smell, 611. 679 

 Smith, H. W., 253, 254 

 Snail, 71, 178, 630, 631-643, 644, 798 

 Snakes, 666, 713, 716, 718, 799 



boa constrictor, 720 



cobra, 719 



garter, 714, 721 



rattlesnake, 714, 721 

 Sneeze, 241 

 Snore, 241 



Social hierarchies, 102 

 Soddy, 12 



Sodium. 174, 199. 200, 267 

 Sodium chloride, 198 

 Soft palate, 182, 206 

 Soft-shelled turtle, Florida, 726 

 Sol, 21, 22, 26-28 

 SoUd, 19-21 

 Solution, 19, 21 

 Somatopleure, 367, 370 

 Species, 67, 777, 795 



living, number of, 69 

 Sperm, 331, 335, 336, 341, 405 

 Spermatheca, 612 

 Spermatogenesis, 43, 44, 46, 406 



Spermatogonia, 43, 44 



Spermatophores, 684 



Spermatophyta, 796 



Sphaeridae, 642 



Sphenodon pnnctatiiiu. 111, 782, 799 



Sphenoidal sinus, 270 



Sphincter valve, 251 



Spicules. 456, 458. 459. 464 



Spiders, 622, 623-626, 663, 798 



anatomy, external. 624 

 internal. 625 

 Spinal cord. 238, 251 



frog, 704 



human. 298 

 Spinal nerves, 293, 707 

 Spindle. 41. 42, 46 

 Spinnerets, 624 

 Spiracles, 602, 604, 608, 618 

 Spirometer, 240 



Spirostonuiin ainbigituni, 426, 428 

 Splanchnopleure, 367, 370 

 Spleen, 216, 225, 697 

 Sponges, 454, 455, 456-464 



reproduction, 459-462 



skeleton, 457, 459 



uses, 463, 464 

 Spongilla, 460-462 

 Spongin, 459 

 Spongocoel, 456, 457 

 Sporozoa, 432, 444 

 Sporozoites, 445, 447 

 Spring peeper, 682 

 Squamata, 718-722 

 Squid, 630, 631, 633, 645-650, 798 



giant, 70 

 Stamens, 54, 64 

 Stapes. 316, 319, 320 

 Starch, 30, 32 

 Starfish, 70, 651, 653-661, 798 



appearance, 655 



arm, cross section of, 658 



canals, 656, 657 



development, 659 



eating, 652 



eyespot, 657 



larva, 664 



locomotion, 657 



water vascular system, 656 

 Starling. 192, 255 

 Statoblast, 547 



Statocyst, 481, 495, 497, 583, 584 

 Statolith. 315, 316, 583 

 Statoreceptors, 314, 315 

 Steapsin. 187, 191 

 Stentor, 111 



coernlens, 426 



polymorphitm, 428 

 Sternum, 150, 151. 720 

 Sterocoral pocket, 625 

 Steroids, 257 

 Stevens, N., 406 



