226 



GEORGE W. CORNER 



foi'e a flow thr()ii*>;h the plexus, at a period before the appearance 

 of the main duct. 



These observations offer a ci[uite new and very clear explana- 

 tion of the origin of variations in the pancreatic ducts, which 

 have been a favorite subject of study since the days of Wirsiing 

 and Santorini. The most recent contribution is that of Baldwin 

 ('11) who studied in the human not only the well-known varia- 

 tions as to the presence or absence of an accessory duct, but also 



Bile Duct. 



Accessory 

 Pancreatic Duct 



Pancreatic Duct 



Head of Pancreas 



Fi^. 11 From Baldwin (11) showinj^ an abiionnal loop found in the main pan- 

 creatic duet in three out of one hundred autopsies. 



abnormalities in the course of the ducts within the gland. The 

 latter sort of irregularities have always been attributed to abnor- 

 mal development or growth of one or both anlagen; liut to pro- 

 duce some of the anomalies mentioned by Baldwin (fig. 11) the 

 anlagen must have twisted themselves, as they grew, into loops 

 and spirals; yet in these specimens the outer form and relations 

 of the pancreas are normal. The theory falls when we see, as is 

 clearly shown in figure 7, that before the chief duct is formed, 

 the two anlagen are completely fused, so that the anlagen play 

 no great part in the production of variations in the course of the 

 ducts, except so far as they limit the plexus to one, or at most two, 

 points of outlet into the duodenum. On the other hand the 

 primitive plexus explains all the variations, and the abnormalities 



