A. A. W. HUBRECHT. 
bo 
Cuar. 
Monodelphian and Didelphian Mammals . 
1. The Mammalian Morula 
2. The Origin of the Entoderm : 
3. Developmental Phases of the Embryonic Didente Shield 
4. The Mammalian Gastrula : 
5. Theoretical Speculations about the Origin of the Tronhes 
blast 
B. Ornithodelphian Mammals Se Sree 
C. Ichthyopsids ‘ : 
Il. FurrHer DEVELOPMENT OF THE TWO GERM-LAYERS OF THE VER- 
TEBRATES UP TO THE APPEARANCE OF THE SOMITES. 
I. Mammalia, Mono- and Di-delphia : 
1. Developmental Processes in the Entoderm . 
a. The Protochordal Plate 
4. The Annular Zone of Proliferation 
2. Developmental Processes in the Ectoderm . 
a. The Protochordal Wedge 
. The Ventral Mesoblast 
3: a Relations between the Centres of Proliferation 
II. Amphibia 
III. Sauropsida and Grnitiedenetia 
IV. Fishes 
V. Summary of Cliapters I and Il ’ 
III. DieLorrornoptast (= SeRous = SuBzonaAL AP antane Cuo- 
RION, AMNION, UMBILICAL VESICLE, AND ALLANTOIS IN 
ONTOGENY AND PHYLOGENY 
1. Chorion and Amnion 
2. The Umbilical Vesicle 
3. The Allantois : 
IV. THe part PLAYED BY THE TROPHOBLAST IN THE NuTRITION 
AND ATTACHMENT OF THE EMBRYO 
1. Didelphia Non-placentalia 
2. Monodelphia 
a. Hedge-hog 
6. Primates 
e. Rodents and Carnivores 
d. Other Insectivores, Ungulates, Bdcniates: atl ietivtes 
3. Didelphia placentalia 
V. Dirrerent Aspects and Devaits or PLACcENTATION. 
1. Embryonic (Trophoblastic) and Maternal (Trophospongian) 
Preparatory Processes 
a. Insectivora 
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