594 



INDEX. 



Shell, i. 96, 194 

 Shell, formation of, i. '206 

 Shell of echinus, i. 189 

 Shell of lobster, i. 262 

 Sheltopusic, i. 407 

 Shrapnell, ii. 381 

 Shrew, ii. 350 



Shuckard, i. 306 ; ii. 432, 435 

 Shuttle-bone, i. 457 

 Silica in plants, ii. 38 

 Silurus, i. 385; ii. 278, 349 

 Sinistral shells, i. 217 

 Sinus medianus, ii. 384, 392 

 Sinus utriculosus, ii. 384 

 Sinus venosus, ii. 245 

 Siphonaria, i. 225 

 Siphuncle, i. 239 

 Sipunculus, ii. 217 

 Siren, i. 407 ; ii. 248, 292, 566 

 Skate, ii. 274, 443 

 Skeleton, i. 326 

 Skeleton of leaf, i. 83 

 Skimmer, ii. 118 

 Skin, i. 97; ii. 338 

 Skull, i. 339 

 Slack, i. 57 ; ii. 45 

 Sleep, ii. 476 



Slips, propagation by, ii. 525 

 Sloth, i. 441,463; ii. 258 

 Slow-moving quadrupeds, ii. 258 

 Slug, ii. 430 

 Sviee, i. 332 

 Smell, ii. 354 

 Smith (T), ii. 147 

 Snail, i. 228 ; ii. 430 

 Snake-lizard, i. 399 

 Soemmerring , ii. 516 

 Soils, fertility of, ii. 15 

 Solar light, ii. 423 

 Solen, i. 199 

 Solipeda, i. 456; ii. 170 

 »S'o%, ii. 312 



Sonorous undulations, ii. 371 

 Sorex, ii. 121, 397,451 

 Sound, ii. 371 ^ 



Sound in fishes, i. 382 

 Soup diet, effects of, ii. 168 

 Spallanzaid, i. 53 ; ii. 70, 152, 

 154, 163, 264,302,509,551 



Sparoides, i. 385 

 Spatangus, i. 186 

 Spectra, ocular, ii. 467 

 Spectre of the Brocken, ii. 473 

 Speed of birds, i. 524 

 Speed of fishes, i. 386 

 Speed of quadrupeds, i. 440 

 Spermaceti, i. 429 

 Sphenoidal sinus, ii. 358 

 Spherical aberration, ii. 420 

 Sphincter muscles, i. 125 

 Sphinx, i. 311, 319; ii. 191, 



223, 491 

 Spicula in sponge, i. 140 

 Spider, i. 252; ii. 391, 433 

 Spider-crab, ii. 489 

 Spider-monkey, i. 355; ii. 351 

 Spinal cord, or marrow, ii. 497 

 Spine, i, 346 

 Spines, i. 103 

 Spino-cerebral axis, i. 345 

 Spinous process, i. 350 

 Spiracles, ii. 280 

 Spiral, logarithmic, i. 218 

 Spiral stems of plants, i. 78 

 Spiral threads in plants, i. 59 

 Spiral valve in fishes, ii. 182 

 Spiral vessels, i. 64 

 Spirits, animal, ii. 506 

 Spirula, i. 216 

 Spix, i. 356 ; ii. 395, 484 

 Spleen, ii. 198 

 Splint bones, i. 457 

 Spokes, curved spectra of, ii. 466 

 Spondylus, ii. 429 

 Sponge, i. 135 ; ii. 75, 483 

 Spongioles, i. 69; ii. 18 

 Spotted cells of plants, i. 60 

 Spring-tail, i. 266, 267 

 Spur of cock, i. 518 

 Spurious legs, i. 280 

 Squalus. See Shark 

 Squalus pristis, ii. 149 

 Squirrel, i. 463 

 Squirrel, palm, ii. 159 

 Stability of trees, i.'71 

 Stability. of human frame, i. 477 

 Stag, i. 450 

 Stag-beetle, i. 321 



