INDEX 



665 



Rhythms of plant Hfe, 23 

 Ribs, 331 

 Ricca, 73, 371 

 Riddle, Oscar, 467 

 Rind, 250 

 Ring canal, 336 

 Ritter, W. E., 528 



Rockefeller Sanitary Commission, con- 

 trol of hookworm by, 616 

 Rocky Mountain spotted fever, 222 

 Rodentia, 115 



Rods and cones, 358, 359, 360 

 Rogers, 391 

 Root 



dicotyledonous, 243 



perceptive region of, 373 



tooth, 286 



work of, 243-245 

 Root hair, 24^-245 

 Rosa, 312 



Roses, S39, 505, 515 

 Ross, 406 



Rotifers, 89, 103, 413 

 Roundworms, 87, 103, 219 

 Roux, Wilhelm, 527, 632 

 Rubner, 312 

 Rugae, 289 

 Rumen, 28S 



Ruminant stomach, 288 

 Russian thistle, adaptations for seed 



scattering, 39 

 Rusts, 228 



Saccharomyces, 71 

 Saccharomycetes, 71 

 Sacculina, 500 

 Sagitta, 93 



Salamanders, 103, 109 

 Salivary glands, 293 

 Salmon 



egg-laying habits of, 596-597 



depletion of, 597 

 Sanborn, 453 

 Saprolegnia, 71 

 Saprophytic nutrition, 281 

 Saprophytism, effect on biological 



adaptations, 492 

 Sap-wood, 246, 247 

 Sarcodina, 77 

 Sarcolemma, 338 

 Sauropsida, 507 

 Scab mites, 216 

 Scandinavians, 562 

 Scaphopoda, 97 

 Scarlet fever, 633-634 

 Scavengers, 52-53 

 Schaefifer, A. A., 382 

 Schick test, 633 

 Schizogony, 227 



Schizomycetes, 71 



Schlerenchyma, 247 



Schuchert, estimate of geological time 



by, 553 

 Schwann's sheath, 340 

 Sclerotic coat, 359 

 Scolex, 226 

 Scorpions, 500, 514 

 Scott, W. B., 510 

 Scurvy, 278 

 Scyphozoa, 81 

 Sea-anemones, 81 

 Sea-cows, 117 

 Sea-cucumbers, 95 

 Sea-lilies, 328 

 Sea-urchins, 95, 103, 334, 459, 485, 



505, 531 

 Sea-walnuts, 83 

 Secondary oocyte, 430 

 Secondary sexual characters, 398 

 Secondary spermatocyte, 430 

 Secretin, 310, 392 

 Sedges, 506 



Sedimentary rocks. 475 

 Seed, 435, 490 



formation of, 62, 270-272 



methods of scattering, 39 



uses of, 272 

 Segmentation, 294 

 Segregation, 447, 450 

 Selaginella, 75 

 Selection, 452 



artificial, 452 



germinal, 527 



mass, 453 



natural, 443, 452 



progeny, 453 



sexual, 527 

 Sella turcica, 350 

 Semicircular canal, 361 

 Semilunar valves, 304, 308 

 Seminal receptacles 



bee, 212 



earthworm, 196 

 Seminal vesicles 



bee, 212 



earthworm, 196 

 Semper, 436 

 Sense organs, 498 



Sensitive plant, responses in, 575-374 

 Sensitivity, definition of, 127 

 Sepals, 497 



Septa, earthworm, 188, 189 

 Serology, 514 

 Serosa, 290 

 Serum, 311 

 Setae, 188, 193, 334 

 Sex, 465, 470 



beginnings of, in algae, 169-172 



