476 



INDEX 



Saliva, 80, 162, 245 



Salivary glands, 75, 159 



Salts, 13 



Sap vacuole, 40 



Saprophytic plants, 43 



Saprozoic animals, 43 



Sarcodina, 54, 97, g8 



Scales, 118, 144 



Scaphopoda, ///, 112 



Scapula, 1^0 



Schizophyta, 76, 77 



Schwammerdam, 422 



Science, i, 421-438 



Science of Biology, i, 421-438 



Scientific method, 426 



Sclerotic coat, 226, 228 



Scolex, 104, 364, 365 



Scyphozoa, loi, 102, 258, 261 



Sea anemone, 102, 103 



Sea cow^, 123 



Sea cucumber, 109 



Sea squirts, 114, 7/5, 296 



Sea urchin, 108, 109 



Sea walnut, 103 



Seals, 122 



Sebaceous glands, 145, 146 



Secondary sex organs, 196 



Secretions, 243 



Segmental animals, 138 



Segregation, 323 



Selection, 343 



Selection in breeding, 342, 343 



Semicircular canals, 230, 232, 233 



Seminal vesicle, 199 



Seminiferous tubules, 799 



Semipermeable membranes, 32, 234 



Senescence, 53, 299-302 



Sensory nerves, 211 



Septae, 138, 754 



Septicemia, 82, 83 



Serial homology, 141, 142 



Sertoli cells, 200 



Serum therapy, 86 



Serums, 86 



Sex chromosome, 309, _j7j, J76, J75 



Sex determination, 334, 335 



Sex hormone, 334 



Sex reversal, 334 



Sex-limited inheritance, 330 



Sexual reproduction, 75, 192 



Shark, 73, 777, 118, 142, 158 



Shark sucker, 73 



Shoulder girdles, 750 



Simiidae, 122 



Sino-auricular node, 238, 239 



Sinus venosus, 779, 180, 238, 239 



Sirenia, 123 



Skin, 145, 146, 190, 244 



Sloth, 121 



Slug, 112 



Small intestine, 158, 759, 760, 767, 470 



Smallpox, 84-86 



Smell, 223, 224 



Smuts, 77 



Snails, 777, 112, 375 



Snakes, 119, 192, 355 



Social life, 384, 385 



Sodium, 7 



Sodium chloride, 13 



Soil fertility, 44 



Solutions, II, 21 



Soma, 309 



Somatic number, 309 



Sori, 192, 255 



Special creation, 418 



Special senses, 223 



Species, 54, 96, 304 



Species adaptation, 347 



Speed of nerve impulse, 235 



Spencer, 390 



Spermary, 92, 259 



Spermatid, J7i, 314, 315 



Spermatocyte, 57 j, 314, 315 



Spermatogenesis, 312, i7j-3i5 



Spermatogonia, 312, j7j 



Spermatophyta, 77, 252, 255, 257 



Spermatozoa, 90, 193, 794, 199, 200, 



251, 305, 312, 313 

 Spherical symmetry, 134 

 Spicules, 100, 142, 143 

 Spiders, 112, 77_j, 114, 767, 414 

 Spinal accessory nerve, 223 

 Spinal cord, 276, 218 

 Spinal nerves, 276, 221 

 Spiracles, 765 

 Spiral valve, 755 



