xxviii LIST OF ILLUSTRATIONS 



FIG. PAGE 



82. Transverse section of an Embryo Chick in the latter half 



of the second day, at the place where the Vertebral 

 Somites cease - - 222 



83. Transverse section through the Embryo of the Chick and 



Blastoderm on the second day - - 222 



84. Diagrammatic longitudinal sections of Elasmobranch Embryo 



and Blastoderm - - 223 



85. Diagrammatic longitudinal section of an Embryo of Lacerta 223 



86. Outlines showing the relation of the Axis of the Embryo to 



the Ovum in Birds and Mammals - - 224 



87. Outline of the Embryo-Chick at the end of the third day, 



to show the inflections of the Body and the commence- 

 ment of the Limbs - - 225 



88. Ovum of the Rabbit from the Fallopian Tube, twelve hours 



after impregnation - - 229 



89. Front and side views of an early Human Ovum four times 



the natural size - 229 



90. Human Ovum of 12 to 13 days - 230 



91. Human Ovum and Embryo of about 14 days 230 



92. First stages of Segmentation of a Mammalian Ovum; semi- 



diagrammatic - - 231 



93. Sections of the Ovum of the Rabbit during the later stages 



of Segmentation, showing the formation of the Blastodermic 

 Vesicle - - 232 



94. Pyriform transparent area of the Chick's Blastoderm with 



the Primitive Groove- - 233 



95. Embryonic area from the Ovum of a Rabbit of eight days 233 



96. Surface view of the transparent area of a Blastoderm of 



1 8 hours, somewhat diagrammatic - 234 



97. Brain and Spinal Cord exposed from behind in a Foetus of 



three months - - 235 



98. Lateral view of the Brain of an Embryo Calf of 5 cm. - 236 



