TABLE OF CONTENTS. 



PART II. THE HISTORY OF THE MAMMA- 

 LIAN EMBRYO. 



iNTBODnCTION, pp. 3O7, 308. 



CHAPTER X. 



Genbeal Development of the Embryo . . pp. 309 — 341. 



The ovarian ovum, 309, 310. The egg-membranes, 310. Ma- 

 turation and impregnation, 310 — 312. Segmentation, 312 — 314. The 

 blastodermic vesicle, 314 — 316. The formation of the layers, 316 — 

 320. The primitive streak and groove, 319, 320. The medullary 

 groove, 320, 321. The mesoblast, 321 — 325. The notoohord, 325, 326. 

 The rudiment of the neurenterio canal, 326. Eecapitulation, 326. 

 The vascular area, 326. General growth of the embryo, 327 — 334. 

 The human embryo, 335 — 341.. Embryos of guinea-pig, etc. with so- 

 called inversion of the layers, 341. 



CHAPTER XL 



Embbyonio Membranes and Yolk-Sao . . pp. 342 — 364. 



The typical development of the embryonic membranes, 342 — 352. 

 Vascular area of rabbit, 343 — 346. The yolk-sao or umbihcal vesicle ; 

 amnion, 343. The subzonal membrane, 346. Attachment of blasto- 

 dermic vesicle to uterine walls, 347. The formation of the chorion, 

 348. Mesoblast and blood-supply of the aUantois, 348, 349. The 

 placenta, 349, 350. The fate of the embryonic membranes, 350 — 352. 

 Deciduate and non-deoiduate type of placenta, 352. Comparative 

 history of the mammalian fcetal membranes, 352 — 359. Fcetal mem- 

 branes of Monotremata and Marsupialia, 352. The disooidal pla- 

 centa, 353, 354. The metadiscoidal placenta, 354 — 358. The zonary 

 placenta, 358, 359. The difEuae and polycotyledonary placenta, 359. 

 Comparative histology of the placenta, 359 — 363. Evolution of the 

 placenta, 364. 



