INDEX 



Radial symmetry, 222; of coelenterates, 284, 

 285; of echinoderms, 508 



Radiata, 219, 221, 223, 225, 286; and Bi- 

 lateria, 312-313 



Radiolaria, 230, 236, 238, 263 



Radiolarians, 527 



Radula, of chitons, 382; of gastropods, 384; 

 of squid, 392 



Rana calesheiana, 218; R. clamilam, 218, 567; 

 R. palustm, 215, 218; R. pipiem, 218; R. 

 sylraltca, 218 



Random combination, 184, 190 



Ranidae, 217-218 



Rat, 580 



Rattlesnake, 571 



Ray, John, 215 



Ray-finned fishes, 541, 557 



Rays, 541, 556, 557 



Reassociation, in sponges, 281 



Recapitulation, 429 



Recapitulation Theory, 225, 313, 633 



Reception, 68, 105-113 



Receptor-adjustor-efTector nervous system, 

 297, 524 



Receptor-effector nervous system, in coelen- 

 terates, 523; in Hydra, 297; in sponges, 522, 

 523 



Receptors, 91, 96, 100; for pain, 110; for 

 taste, 110; for temperature, 110; for touch, 

 110; light-sensitive, 106; of ear, 108; ol- 

 factory, 109 



Recessive character, 175, 177 



Reciprocal cross, 182, 193 



Rectal caeca, 491 



Rectum, 50 



Red blood cells, see Erythrocytes 



Redi, Francesco, 259, 330 



Redia, of Clonorchis, 330 



Reduction bodies, of sponges, 281 



Reflex action, 95 



Reflex arc, 96 



Reflexes, of breathing, 102; of tongue, 102; 

 of vision, 102 



Refractory period, 1 1 2 



Regeneration, 530; in Hydra, 299; in oligo- 

 chaetes, 412; in planarians, 322, 323; in 

 sponges, 281; in starfish, 497 



Regional specialization, in annelids, 421; in 

 arthropod evolution, 484; of digestive sys- 

 tem, 512 



Reindeer, in cave paintings, 642 



Rejuvenation, in ciliates, 257 



Renal artery, 58, 83 



Renal corpuscle, 58 



Renal portal veins, 51, 58 



Renal tubule, see Nephron 



Renette cells, 349, 351 



Rennin, 71 



Reproduction, 13, 128, 139-145, 634; asexual, 

 in Echinococcus , 340; asexual, in ectoprocts, 



702 



361; asexual, in hydra, 300; asexual, in 

 Melndium, 306; asexual, in oligochaetes, 

 416, 417; asexual, in Slenostomum, 325; in 

 Acanthocephala, 354; in amoeba, 235-236; 

 in Anledon, 508; in Arbacia, 501; in arthro- 

 pods, 533; in Ascans, 352; in Brachiopoda, 

 364; in Bu^ula, 360; in cephalopods, 390; in 

 coelenterates and ctenophores, 531; in cray- 

 fish, 435; in digenetic trematodes, 331-332; 

 in earthworm, 410; in Euglena, 241, 242- 

 243; in gastropods, 386; in Gonium, 266; in 

 Hydra, 297; in locust, 452-454; in Mesozoa, 

 270, 531; in mollusks, 533; in nematodes, 

 351; in nemertines, 343; in .\ereis, 401; in 

 pelecypods, 375; in planarians, 320-322; in 

 Porifera, 280, 531; in rhabdocoels, 326; 

 in rotifers, 346-348; in starfish, 496; meth- 

 ods of, 141; regulation of, 122-124 



Reproduction and development, of ascidians, 

 547; of balanoglossids, 543; of Branchwsloma, 

 552; of Thyone, 506 



Reproductive ducts, 128 



Reproductive mechanisms, of invertebrates, 

 comparative, 531, 532 



Reproductive organs, 128 



Reproductive potential, of cabbage aphid, 

 609; of elephants, 609; of Paramecium, 610 



Reproductive system, in Acanthocephala, 355, 

 533; in Ascans, 350, 352; in earthworm, 

 410, 411; in locust, 448; in nematodes, 

 349, 350, 351; in planarians, 320-322; in 

 rotifers, 345, 346-347; in starfish, 496; in 

 tapeworm, 336-337; in trematodes, 328, 

 329; in vertebrates, 128-133, 156; in ver- 

 tebrates, female, 130; in vertebrates, male, 

 129 



Reproductive systems, in animals, 511; 

 in annelids, 533; in invertebrates, 529- 

 535; in nematodes, 533; in Platyhelminthes, 

 532 



Reptiles, adapted to desert life, 602; brain, 

 86; diversification of, 566; embryo, 157; 

 embryonic development of, 634; replace- 

 ment by mammals, 591 



Reptilia, 216, 541, 565-573 



Respiration, 79-82 



Respiratory center, 102, 124 



Respiratory organs, 54; of crustaceans, 516; 

 of echinoderms, 516; of pelecypods, 516; 

 of polychaetes, 516; of pulmonale gastro- 

 pods, 517; of terrestrial isopods, 517 



Respiratory pigments, 29 



Respiratory system, of vertebrates, 54-56, 154 



Respiratory systems, general functions of, 517; 

 of invertebrates, 516-517 



Response, 113-114; 116 



Responsiveness, 13, 634; in amoeba, 232 233; 

 in crayfish, 433; in earthworm, 409; in 

 Euglena, 241 242; in Hydra, 293; in in\erte- 

 brates, 521 527; in locust, 451; in I'ara- 



