514 



F. H. EDGEWORTH. 



There are three median hyobranchial cartilages in Gallus. 

 Parker called them the cartilage entoglossa, basihyal, and 



Aban. -. 



eph coel 



Text-fig. 4. — Sagittal section through embryo of Gallus, with 

 2 fully formed and 1 partially formed gill-pouch. (For explana- 

 tion of lettering see p. 555.) 



urohyal, and stated tliatthe first named was formed by lateral 

 fusion of the lower ends of the ceratohyals. Geoffrey Smith 



ygnt 



tr art 



fcnt ceph ctr/ 



Text-fig. 5. — Sugittal section through cmlirjo of Gallus, with 

 3 gill-pouches. From the anterior portion of the gut a hollow 

 pouch projects laterally, tlie wall of which is cut by this section 

 (the Anlage of the premandibular segment). (For explanation of 

 lettering see p. 555.) 



