LIST OF ILLUSTRATIONS. XIX 



FIG. TAGE 



66. Diagram of the Condition of the Arches of the Aorta towards the 



Close of Incubation 216 



67. Diagram of the Arterial System of the Adult Fowl . . .219 



68. View from above of the Investing Mass and of the Trabecule on 



the Fourth Day of Incubation ....... 226 



69. View from below of the Paired Appendages of the Skull of a Fowl 



on the Fourth Day of Incubation . . . . • .229 



70. Side view of the Cartilaginous Cranium of a Fowl on the Seventh 



Day of Incubation ......••• 231 



71. Embryonic Skull of a Fowl during the Second "Week of Incubation 



(third stage) from below . . . . . . • -234 



