Daniel G. Revell 



455 



d.S. 



dua. 



d.W 





'v.p.d.s. 



a.p.d.s. 

 d.c. 



~\ 



Fig. 14. — Part of the duodenum, ductus 

 choledochus, pancreatic ducts and superior 

 pancreatico-diiodenal vessels, seen from the 

 risrht side. 



left formed the left (splenic or omental) limb (cauda pancreatis); it 

 contained the ductus Santorini, which did not bifurcate. The 

 pancreatico-duodenal vessels ran between the two divisions of the 

 pancreas. There were in fact 

 two pancreatic glands present, 

 (caput pancreatis) right, the 

 other (cauda pancreatis) to 

 the left. In all the other in- 

 stances, in which the ducts 

 were united, the loop formed 

 by the ducts from one orifice 

 to the other arched over the 

 pancreatico-duodenal vessels 

 (Fig. 14). 



Types not met with but which are possible are : 



(a) Ductus Wirsungianus the larger. 



(b) Either duct absent. 



(c) Only one pancreatic orifice. 



The varying size of the ductus Wirsungianus indicates that all these 

 types will be met with in a sufficiently large series. 



Eemarks. — 1. A consideration of the types (Fig. 13) of the ducts in 

 the adult leads to the following conclusions regarding the pancreas of 

 the dog: 



(a) The pancreas has a double origin, arising from at least two 

 anlages, which are placed on opposite sides of the pancreatico-duodenal 

 vessels, but unite beyond these so as to form an arch over them. 

 (Fig. 14). 



(b) The original fields of the two ducts (and of the two anlages) are: 

 (i) ductus Wirsungianus (ventral anlage), the caput pancreatis (duo- 

 dorsal segment) and the right half of the basal or epiduodenal (vide 

 infra) segment; (ii) ductus Santorini (dorsal anlage), the remainder of 

 the gland.* By the anastomosis which occurs where these two fields 

 are contiguous, the ductus Santorini takes over the drainage of the 

 field of the ductus Wirsungianus beyond the anastomosis. 



(c) These facts justify giving distinctive names to the two segments 

 of the right limb of the pancreas : the anterior part, applied to the duo- 

 denum consists of the proximal or basal part of the product of each 



3 This accounts forFlexner's observations in his study of experimental pancreatitis. 

 He injected the ductus Santorini — not the ductus Wirsungianus — with various fluids, 

 and observed immediate and subsequent effects most marked in the splenic and hasal 

 parts of the gland. 

 31 



