JORDAN XIV 







8. Sinistro-dorsal portion ot transverse section of 32-dav enil)rvo at level of transition 

 from esophagus (e) to the stomach. The apparent obliquity of the section is due 

 to the sinistral rotation of the cardiac end of stomach (c. s) . The approximatelv 

 transverse position of stomach at these stages accounts for its being cut longitud- 

 inallv in a transverse section of the embrvo. Note the extensively fenestrated 

 condition of the caudal portion of the esophagus (e, within the rectangle) at this 

 stage. (r),rib; (c), pleural cculom ; (/),left lung; (rt), '"ight dorsal aorta ; (ft), right 

 primarv bronchus. Photo, x 17. 



!♦. More highlv magnified photomicrograph (x 300), of portion of esophagus included 

 within rectangle in preceding figure, (x), earlier irregular and several-layered con- 

 dition of lining epithelium of esophagus during period of fenestration of solid 

 esophagus in the process of reestablishment of patency of its lumen ; (y), a delicate 

 nucleated septum, in process of reincorporation within the later regular single- 

 lavered lining of the open esophagus; («), portion where lumen is lined with the 

 later (transient) single-layered epithelium of prismatic cells. 



