PLATYPUS AND ECHIDNA. 



found a pancreatic duct opening into the duodenum inde- 

 pendently of the common duct. The combined duct sur- 

 rounded by pancreatic tissue is traced in the right margin 

 of the lesser omentum, and after running parallel and to 

 the right with the duodenum for 1 cm. enters it at a right 

 angle about 3 cm. from the thickened pylorus in a well 

 developed male, though in a female the distance was only 

 1.75 cm. Thus it forms a loop at its termination. As in 

 the Platypus, this portion is about double in circumfer- 

 ence that of the common duct, but opens into the duo- 

 denum by a distinct papilla, thus differing from that 

 Monotreme. A slight bulbous swelling .75 cm. long is 

 noted on the duct just before it enters the duodenal wall. 

 A valve is noted at the junction of the duct and the bulb- 

 ous swelling. 



Hepatic Ducts in E<-hi<hi<t. — At the portal interval on 

 the right side a well defined trunk (right hepatic) is 

 noted, with branches passing into it from the right mesial 

 — right lateral — and caudate and spigelian lobes. On the 

 left side there may be a single trunk (left hepatic), with 

 branches passing into it from the left mesial and left 

 lateral lobes, or we may have a single branch from the 

 left lateral joining the cystic duct opposite the right 

 hepatic, and nearer the gall bladder a separate branch 

 from the left mesial lobe. A compromise between the two 

 (Hi the left side is depicted in the diagram (page k 3)). 



Pancreatic Duct in Echidna. — Although a single 

 pancreatic duct entering the common duct on the right 

 side is in my experience most frequent, nevertheless the 

 following conditions should be noted: — 



(a) Single duct entering the common duct on the 

 right. It passes parallel with the latter in 

 the gastro-hepatic omentum for about .75 

 cm. 



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