X THE STRUCTURE OF THE FOWL 



46 



47 

 48 

 49 



PAOE 



45. Section of Albumen-secreting Part of Oviduct 



showing the Opening of a Tubular Gland Facing 76 

 Epithelium from Albumen - secreting Part of 

 Oviduct showing Ciliated Columnar and 

 Goblet Cells .... Facing 76 



Diagram of the Chief Arteries . . .82 



Diagram of Chief Veins . . . .84 



Brain seen from the Side . . . .91 



50. Section through the Eyeball . . .99 



51. Section through Coats of the Eyeball at the 



Exit of the Optic Nerve, under Low Magnifica- 

 tion ..... Facing 76 



52. Diagram of the Parts of a Feather . . 105 



53. Diagram of Three Stages in the Gro^^i:h of a 



Feather ..... Facing 108 1 

 Surface View of the Blastoderm showing the 



Lines of Segmentation . . . . 114j 



Diagram of the Blastoderm within the Egg about 



the End of the First Day of Incubation . 117j 

 Primitive Streak and its Surroundings . . 1181 



Transverse Section through the Primitive 



Streak ..... Facing 108 j 

 Transverse Section through the Neural Groove 



Facing 118 

 Transverse Section of Embryo . . „ 118 



61, 62. Diagrams of Transverse Sections of 



Blastoderm to illustrate Extension and 



Splitting of Mesoderm . . . Facing 120 



63, 64. Diagrams of Transverse Sections to illustrate 



the Separation of the Embryo from the rest 



of the Blastoderm . . . Facing 120 



54 

 55 



56 

 57 



58 



59 

 60 



