052 



1XDEX. 



Polygordius, excretory organs of, 564 



Polyophthalmus, eye of, 394 



Polypedates, brood-pouch of, 100 



Polyzoa, excretory organs of, 563 ; gene- 

 rative cells of, 613 ; generative ducts of, 

 618 



Pons Varolii, 351, 352 



Pori abdorninales, Ammoccetes, 81 



Porifera, ancestral form of, 285 ; develop- 

 ment of generative cells of, 610 



Portal vein, 536 



Postaual gut of Elasmobranchii, 47, 48, 

 49 ; Teleostei, 61 ; Chick, 140 ; general 

 account of, 267, 634 



Prasmaxilla, 488 



Prteopercular bone, 487 



Praeoral lobe, ganglion of, 311, 313 



Prefrontals, 490 



Presphenoid region of skull, 470 



Primitive groove of Chick, 128 



Primitive streak, of Chick, 126, 134; 

 meaning of, 127 ; origin of mesoblast 

 form in Chick, 127, 128 ; continuity of 

 hypoblast with epiblast at anterior end 

 of, in Chick, 129 ; comparison of with blas- 

 topore, 137 ; fate of, in Chick, 137 ; of 

 Lacerta, 168 ; of Rabbit, 184 ; of Guinea- 

 pig, 186 ; fusion of layers at, in Rabbit, 

 186 ; comparison of with blastopore of 

 lower forms, 187, 238 ; of Mammalia, 

 241 



Processus falciformis of Ammocretes, 410 ; 

 of Elasmobranch, 413 ; of Teleostei, 414 



Proctodasum, 642 



Pronephros, of Teleostei, 63, 578 ; Pe- 

 tromyzon, 78, 81, 577 ; Acipenser, 88, 

 91 ; Amphibia, 110, 582 ; general ac- 

 count of, 568 ; of Cyclostomata, 577 ; of 

 Myxine, 578; Gauoidei, 581; of Ani- 

 niota, 588 ; of Chick, 5'Jl ; summary of 

 and general conclusions as to, 600 ; 

 relation of, to rnesonephros, 603 ; cause 

 of atrophy of, 601 



Prootic, 489, 490 



Propterygium, 506 



Proteus, branchial arches of, 117 



Protochordata, characters of, 271 



Protoganoidei, characters of, 272 



Protognathostomata, characters of, 271 



Protopentadactyloidei, characters of, 272 



Protovertebrata, characters of, 271 



Pseudis, Tadpole of, 115 ; vertebral column 

 of, 458 



Pseudophryne, yolk-sack of, 115; Tadpole 

 of, 116 



Pterygoid bone, of Teleostei, 478 ; origin 

 of, 488 



Pterygoquadrate bar, of Elasmobranchii, 

 474; of Teleostei, 478; Axolotl, 4 0; 

 Frog, 481; of Sauropsida, 484 ; of Mam- 

 malia, 484 



Pulmonary artery, origin of, 530 ; of 

 Amphibia, 531 ; of Arnniota, 533 



Pulmonary vein, 538 



Pupil, 402 



Pyrosoma, development of, 19 



Quadrate bone of Teleostei, 478 ; of Axolotl, 



480 ; Frog, 481 ; Sauropsida, 484 

 Quadratojugal bone, 488 



Rabbit, development of, 177; general 

 growth of embryo of, 188 ; placenta of, 

 199 



Radiate symmetry, passage from to bi- 

 lateral symmetry, 308 310 



Raja, caudal vertebra of, 455 



Rat, placenta of, 200 



Reeessus labyrinthi, 427 



Reissuer's membrane, 432 



Reptilia, development of, 167 ; viviparous, 

 167 ; cerebellum of, 350 , iufundibulum 

 of, 355 ; pituitary body of, 359 ; cere- 

 brum of, 361 ; vertebral column of, 

 458; arterial system of, 532; venous 

 system of, 539 ; rnesonephros of, 588 ; 

 testicular network of, 596 ; spermatozoa 

 of, 615 



Restiform tracts of Elasmobranchii and 

 Teleostei, 350 



Retina, histogenesis of, 404 



RetinuL-e, 396 



Rhabdom, 396 



Rhinoderma, brood-pouch of, 100 ; meta- 

 morphosis of, 115 



Ribs, development of, 462 



Rosenm tiller's organ, 597 



Rotifera, excretory organs of, 561 



Round ligament of liver, 546 



Ruminantia, placenta of, 211 



Sacci vasculosi, 355 



Sacculus hemisphericus, 427 ; of Mammals, 

 428, 429 



Sagitta. See ' Chastognatha ' 



Salpa, sexual development of, 24 ; asexual 

 development of, 28 



Salamandra, larva of, 117; vertebral 

 column of, 456 ; limbs of, 509 ; rnesone- 

 phros of, 583 ; Miillerian duct of, 585 



Salmonidfe, hypoblast of, 57 ; generative 

 ducts of, 580 



Sauropsida, gastrula of, 238; meaning of 

 primitive streak of, 239 ; blastopore of, 

 240 ; mandibular and hyoid arches of, 

 483 ; pectoral girdle of, 493 



Scala, vestibuli, 430 ; tympani, 430 ; media, 

 430 



Scales, general development of, 327 ; de- 

 velopment of placoil scales, 326 



Scapula, 492 



Sclerotic, 401 



Scrotum, development of, 599 



Scyllium, caudal vertebra? of, 455 ; mandi- 

 bular and hyoid arches of, 476 ; pectoral 



