540 



INDEX 



)2 



Ptarmigan, 46i 

 Ptyalin, 125, 172 

 Pubis, 115 



Pulmocutaneous arch, 73 

 Pulmonary veins, 76 

 Pulvillus, 421 

 Purkinje, 39 

 Pylangium, 77 

 Pyloric caeca, 365 



valve, 160 

 Pyrenoid bodies, 282 

 Pyridoxine, 175 



Quadroon, 243 

 Quadrula, 374 



Q 



R 



Radial nerve, 368 



symmetry, 303 

 Radiata, 358 

 Radiolaria, 271, 280 

 Radula, 386, 387 

 Ramus communicans, 140 

 Ranacatesbeiana, 65 



grylio, 65 

 Rat, 107 



external structure, 108 

 muscular system, 115 

 reproductive system, 142 

 Rattus alexandrinus, 107 

 norvegicus, 107 

 rattus, 107 

 Ray, 34 

 Rays, 148 

 Recapitulation theory, 163, 224, 413, 



487, 501 

 Recessive, 237 

 Rectal caeca, 365 

 Rectum, 124 

 Rectus abdominis, 90 

 Redia, 449 



Reduction division, 210 

 Reflex, 325 



arc, 133, 182 

 Regeneration in crayfish, 409 

 in earthworm, 355 

 in Hydra, 322 

 in Planaria, 333 

 in starfish, 370 

 Regions of life, 473 



zoogeographical, 472 

 Relations of animals and plants, 26 

 Remak, 50 

 R-enal pelvis, 140 



portal system, 7(5 

 Renilla, 3il 

 R^nnin, 122, 169 

 Reproduction, Ascaris, 340 

 bisexual, 192 



Reproduction — Cont 'd 



development of sexual, 61 



function of, 191 



Hydra, 319 



in Amoeba, 289 



in crayfish, 407 



in earthworm, 352 



in Euglena, 284 



in Paramecium, 290 



of starfish, 368 



sexual, 209 

 Reproductive system of frog, 95 

 of rat, 142 

 of vertebrates, 164 

 Reptilia, 148 

 Respiration, aerial, 177 



as function, 176 



external, 160, 177 



in Euglena, 284 



internal, 160, 177 

 Respiratory system, development, 



of vertebrate, 161 

 Resting cell, 50 

 Retina, 94 

 Retinula, 405 

 Retractors, 116 

 Rhabdocoelida, 323 

 Rhabdome, 405, 406 

 Rhabdopleura, 147 

 Rheotropism, 278, 325 

 Rhizopoda, 270 

 Rhomaelia, 422 

 Rhombencephalon, 218 

 Rhynchocephalia, 486 

 Riboflavin, 175 

 Ribs, false, 114 



true, 113 

 Rickets, 175 

 Rise of horse, 492 



man, 494 

 Rodentia, 107 • 

 Roe, 371 



Ross, Major Ronald, 280 

 Rostellum, 454 

 Rostrum, 397 

 Rotifers, 24 

 Roundworms, 23, 335 

 Rumina, 382 



S 



Sacculina, 413, 440 

 Sacculus, 94 

 Sagartia, 309 

 Sagebrush formation, 464 



jack rabbit biome, 464 

 Sagitta, 24 

 Salientia, order, 105 

 Salivary glands, 124 

 Salpa, "147 

 Salts, inorganic, 47 



218 



