xx LIST OF ILLUSTRATIONS 



FIG. PAGE 



68. (a) Transverse Section through Embryo during 



Third Day, (6) Diagram of the Circulation of 

 the Yolk-sack 28 1 



69. Hyoid Bone of Crow 282 



70. Diagrams of Aortic Arches {a) on Third Day, (b) on 



Fifth or Sixth Day 283 



71. Diagram showing Aortic Arches in (a) Lizard, {b) 



Bird, (c) Man 284 



72. Wing of Hoatzin (a) Young, (/>) Mature 289 



73. Cone characteristic of the Structure of Blue 



Feathers 299 



74. Snipe's Tail-feather 309 



75. Sternum of Ostrich 383 



76. Spinal Feather Tracts of Snipe and Blackbird . . 384 



77. Albatrosses on Nest 399 



