664 



INDEX 



Protozoa, 77, 103, 151-163, 328, 334, 

 335, 342, 411 



disease-causing, 582 



parasitic, 220 

 Protozoans, 234, 485, 511, 531 

 Protracheates, 315 

 Protylopus, 509 

 Psalterium, 288 

 Pseudopodia, 334, 342 

 Psilotum, 75 

 Psychozoic era, 476, 513 

 Pterodactyls, 513 

 Pteropsida, 75 

 Ptyalin, 293 

 Puff balls, 73 



Pulmonary artery, 308, 317 

 Pulmonary circulation, 309 

 Pulp cavity, 287 

 Pulvini, function of, 374 

 Pupa, bee, 212, 213 

 Pupil, 369 

 Pygmies, 561, 562 

 Pylorus, 289 

 Pyramidal tracts, 351 

 Pyramids, 351 

 Pyrenoids, 170 



Quarantine, reasons for, 635 

 Queen bee, 201, 205, 211, 212, 214 

 Queen cell, 212 



Rabbit brush, 50 



Rabbits, 493, 499, 514, 515 



Rabies, 632 



Raccoons, 115, 546 



Race horses, 453 



Races, 559 



Radial canals, 336 



Radial nerve cords, 343 



Radial symmetry, 343, 531 



Radio-activity, use of, for estimating 



geological formations, 554 

 Radiolaria, 77, 328 

 Radius, 332, 544 

 Rails, 114 

 Rana, 109 



Rancho La Brea, 477 

 Rathke's pocket, 399 

 Ratios, modified, 450 

 /Rats, 115, 545 

 Ray, John, 64 



Reactions to stimuli, 366, 368 

 Recapitulation theory, 501 

 Receiving neurons, 375 

 Receptor-efifector system, 343 

 Receptor neuron, 341 

 Receptors, 376 



Recessive characters, 445, 454 

 Rectum, 292 



Redi, 406 

 Rediae, 413 

 Reduction division, 429 



moss, 176 



Oedogonium, 173 



Spirogyra, 111-172 

 Reed, Walter, 619 

 Reflex actions, 342, 376 

 Reflex arcs, 341 

 Regeneration, 408 



in arthropods, 410 



in Hydra, Jf09 



in Planaria, 409 



in starfish, 409 



in vertebrates, 410 

 Reindeer, 559 

 Rejuvenescence, 417 

 Relations 



between different species, 50-51 



between flowers and insects, 61-&2, 

 Renal corpuscle, 323, 324 

 Renal pyramids, 323 

 Renal tubules, 322, 323 

 Repetition theory, 502, 503 

 Reproduction, 410 



bee, 211-212 



plants, 61, 62, 270-272 

 Reproductive organs, earthworm, 196 

 Reproductive polyp, Obelia, 186, 186 

 Reproductive system, earthworm, 195- 



196 

 Reptilia, 103, 111, 329, 487, 497, 501, 

 513, 533 



fossil armored, 334 

 Resistance to bacteria, 623 

 Respiration 



external, 311 



Hydra, 182 



internal, 311 



plant, 265-266 

 Respiratory center, 318 

 Respiratory papillae, 313 

 Respiratory trees, 313 

 Responses 



causes of, 366 



to gravity, plants, 371-373, 372 



to stimuli, nature of, 369-370 



to water, roots, 370, 373, 374 

 Reticulum, 288 

 Retina, 369, 360 

 Retinular cells, 358 

 Rheas, 113 

 Rheiformes, 113 

 Rhinoceros, 117, 508, 556, 557 

 Rhizoids, mold, 173 

 Rhodophyceae, 71 

 Rhombencephalon, 346 

 Rhynchocephalia, 111 

 Rhynia, 75 



