lO SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 56 



At about the position of the Hue ta the trachea divides into the 

 two bronchi (onlv one shown in the figure), which are somewhat 

 enlarged at the ends to form the lung rudiments, lu. While the 

 trachea and bronchi lie ventrad to the oesophagus, the lungs lie 

 laterad and even dorsad to the oesophagus and cardiac end of the 

 stomach. Caudad to the heart and in the region of the anterior 

 appendages, aa, the oesophagus suddenly enlarges to form the 

 stomach, i', which has now quite the outline of the typical human 

 stomach. 



From the stomach the duodenum, d, extends, following a sort of 

 \'-shaped course, towards the yolk-stalk, ys. In the region of the 

 yolk-stalk it is somewhat enlarged and ends in a blind sac like a 

 caecum. At the side of this sac is seen the opening of the enteron 

 to the yolk-stalk ; the anterior and posterior intestinal portals are not 

 distinguishable from each other. From this point the hindgut, kg, 

 extends cephalad until it lies laterad to the middle region of the 

 duodenum, then bends through i8o° and extends, in an almost 

 straight line, to the cloaca, cl, lying in the region of the posterior 

 appendage, pa. 



The allantois, al, extends cephalad for some distance from the floor 

 of the cloaca. Some distance caudad to the cloaca, near the end of 

 the much coiled tail, is seen the post-anal gut, pag. This structure 

 as has been noted above, is quite distinct from the other parts of the 

 enteron. It is of elongated, pyriform outline, with the pointed end 

 extending cephalad. 



In the narrow space between the stomach and the duodenum is 

 the elongated pancreas, pan, opening by two or more short ducts into 

 the duodenum. 



The liver, li, in the figure under discussion, has about twice the 

 area of the stomach. It extends caudad and dorsal about the same 

 distance as the latter organ, but it extends ventrad and cephalad 

 far beyond the boundaries of the stomach. 



Extending along the ventral border of the liver is a long narrow- 

 duct, apparently the bile duct, bd. It connects, caudally, with the 

 anterior end of the pancreas, while at its other extremity, near the 

 antero-ventral corner of the liver ; it ends blindly. 



The transverse sections now to be described have been selected 

 from the series from which the reconstruction, just described, was 

 made. 



Figure 6b represents a typical section through the pharynx. Its 

 plane is approximately shown by the line 400 of figure 6a though 

 the plane apparently does not cut the eye, e. The pharynx, ph, has 

 here the outline of an irregular V. Its walls, except at the outer 



