790 



INDEX. 



Primitive streak, of Chick, 152, 161; 

 meaning of, 153; origin of mesoblast 

 form in Chick, 154; continuity of 

 hypoblast with epiblast at anterior end 

 of, in Chick, 156; comparison of with 

 blastopore, 165 ; fate of, in Chick, 165; 

 of Lacerta, 203; of Rabbit, 221; of 

 Guinea-pig, 223 ; fusion of layers at, in 

 Rabbit, 224; comparison of with blas- 

 topore of lower forms, 226, 287; of 

 Mammalia, 290 



Processus falciformis of Ammocoetes, 498 ; 

 of Elasmobranch, 502 ; of Teleostei, 503 

 Proctoclseum, 778 



Pronephros, of Teleostei, 78, 701; Pe- 

 tromyzon, 95, 99, 700; Acipenser, 106, 

 no; Amphibia, 134, 707; general ac- 

 count of, 689; of Cyclostomata, 700; 

 of Myxine, 701 ; Ganoidei, 705 ; of 

 Amniota, 714; of Chick, 718; sum- 

 mary of and general conclusions as to, 

 728; relation of, to mesonephros, 731; 

 cause of atrophy of, 729 

 Prootic, 596, 597 

 Propterygium, 616 

 Proteus, branchial arches of, 142 

 Protochordata, characters of, 327 

 Protoganoidei, characters of, 328 

 Protognathostomata, characters of, 328 

 Protopentadactyloidei, characters of, 329 

 Protovertebrata, characters of, 328 

 Pseudis, Tadpole of, 139; vertebral 



column of, 556 



Pseudophryne, yolk-sack of, 140; Tad- 

 pole of, 140 

 Pterygoid bone, of Teleostei, 581; origin 



of, 597 



Pterygoquadrate bar, of Elasmobranchii, 

 576; of Teleostei, 581; Axolotl, 584; 

 Frog, 584; ofSauropsida, 588; of Mam- 

 malia, 589 



Pulmonary artery, origin of, 645 ; of 

 Amphibia, 645 ; of Amniota, 649 



Pulmonary vein, 655 



Pupil, 489 



Pyrosoma, development of, 23 



Quadrate bone of Teleostei, 581 ; of 

 Axolotl, 584; Frog, 585; Sauropsida, 

 588 



Quadratojugal bone, 594 



Rabbit, development of, 214; general 

 growth of embryo of, 227; placenta of, 

 248 



Radiate symmetry, passage from to bi- 

 lateral symmetry, 373 376 



Raja, caudal vertebrae of, 553 



Rat, placenta of, 242 



Recessus labyrinthi, 519 



Reissner's membrane, 524 



Reptilia, development of, 202; viviparous, 

 202; cerebellum of, 426; infundibulum 

 of, 431; pituitary body of, 436; cere- 

 brum of, 439; vertebral column of, 



556; arterial system of, 648; venous 

 system of, 656; mesonephros of, 713; 

 testicular network of, 723; spermatozoa 

 of, 747 



Restiform tracts of Elasmobranchii and 

 Teleostei, 425 



Retina, histogenesis of, 490 



Retinulas, 482 



Rhabdom, 482 



Rhinoderma, brood-pouch of, t2i ; meta- 

 morphosis of, 139 



Ribs, development of, 560 



Rosenmiiller's organ, 725 



Rotifera, excretory organs of, 680 



Round ligament of liver, 663 



Ruminantia, placenta of, 253 



Sacci vasculosi, 437 



Sacculus hemisphericus, 519; of Mam- 

 mals, 519, 520 



Sagitta. See ' Chrctognatha' 



Salpa, sexual development of, 29; asexual 

 development of, 33 



Salamandra, larva of, 142; vertebral 

 column of, 553; limbs of, 619; meso- 

 nephros of, 708; Miillerian duct of, 

 710 



Salmonidas, hypoblast of, 71; generative 

 ducts of, 704 



Sauropsida, gastrula of, 286; meaning of 

 primitive streak of, 288; blastopore of, 

 289; mandibular and hyoid arches of, 

 588; pectoral girdle of, 601 



Scala, vestibuli, 522; tympani, 523; 

 media, 522 



Scales, general development of, 396 ; de- 

 velopment of placoid scales, 395 



Scapula, 599 



Sclerotic, 488 



Scrotum, development of, 727 



Scyllium, caudal vertebras of, 553; man- 

 dibular and hyoid arches of, 578; pec- 

 toral girdle of, 600; limbs of, 610; pel- 

 vic fin of, 614; pectoral fin of, 615 



Segmental duct, 690; development of in 

 Elasmobranchs, 690 ; of Cyclostomata, 

 700; of Teleostei, 701; of Ganoidei, 

 704, 705 ; of Amphibia, 707 ; of Am- 

 niota, 713 



Segmental organs, 682 



Segmental tubes, 690 ; development of in 

 Elasmobranchs, 691 ; rudimentary an- 

 terior in Elasmobranchs, 693 ; develop- 

 ment of secondary, 731 



Segmentation cavity, of Elasmobranchii, 

 42 44; Teleostei, 69, 85, 86; Am- 

 phibia, 122, 125 



Segmentation, meaning of, 331 



Segmentation of ovum, in Amphioxus, 2 ; 

 Ascidia, 9; Molgula, 22; Pyrosoma, 

 23; Salpa, 30; Elasmobranchii, 40; 

 Telostei, 69; Petromyzon, 84; Aci- 

 penser, 102; Lepidosteus, in; Am- 

 phibia, 122, 124; Newt, 125; Chick, 

 146; Lizard, 202: Rabbit, 214 



