LIST OF ILLUSTRATIONS. 



FIG. PAGE 



i. Diagrammatic Section of an Unincubatecl Fowl's Egs: . . . 12 



J 33 



1. A. Yellow yolk-sphere filled with fine granules. B. "White yolk- 

 spheres and ^spherules of various sizes and presenting different ap- 

 pearances ...... 15 



3. Section of a Blastoderm of a Fowl's Egg at the commencement of 



Incubation ...... ..... 18 



4. Section through the Germinal Disc of the ripe Ovarian Ovum of a 



Fowl while yet enclosed in its Capsule . . . . . .19 



5. Surface Views of the early Stages of the Segmentation in a Fowl's 



Egg - 2 



6. Surface View of the G-erminal Disc of a Hen's Egg during the later 



Stages of Segmentation ........ 



©O —— --—a 



7. Section of the Germinal Disc of a Fowl during the later Stages of 



Segmentation .......... 24 



'o 



8. A to N. A series of purely diagrammatic representations introduced 



to facilitate the comprehension of the manner in which the body of 

 the embryo is formed, and of the various relations of the yolk-sac, 

 amnion and allantois ........ 29 — 32 



9. Diagrammatic Longitudinal Section through the Axis of an Embryo. 33 



10. Section of a Blastoderm at right angles to the long axis of the 



Embrvo after eight hours' Incubation ...... 4" 



