416 INTERNAL SECRETIONS OF PANCREAS AND SPLEEN. 



We have followed the course of the blood from the splenic 

 vein and back again to the splenic artery which supplies 

 branches to the pancreas, and we have seen that on its way 

 through the latter the arterial blood surrenders its oxygen to 

 the cells and its splenic substance to the islands. The domi- 

 nant feature of the extrinsic functions of the pancreas is its 

 power to destroy albuminoid toxic bodies, and it is evident 

 that the splenic ferment, the mission of which is merely to 

 unite with trypsinogen to form trypsin, cannot do this alone. 

 It is trypsin that constitutes the antitoxic body, and it is the 

 pancreas, therefore, that supplies it to the organism. How 

 does it penetrate the general blood-stream? 



Now that we have ascertained that the islands of Langer- 

 hans are the seat of manufacture, as it were, of at least a part 

 of this antitoxic agency, and that it collects (combined) in the 

 ampullae, the manner in which the general circulation becomes 

 supplied with it is clear: i.e., the quantity that permeates 

 through the ampullar walls is but a portion of their contents, 

 and the rest is swept away with the blood and reaches the 

 splenic vein through the pancreatic veins. But this does not 

 mean that trypsinogen may not be carried alone in the same 

 manner to the splenic vein and therein combine with the 

 splenic ferment to form trypsin. In fact, this must constitute 

 the prevailing process, if the anatomical distribution of the 

 islands of Langerhans, as observed by Opie, can serve as guide. 



As we have seen, Opie found that the islands of Langer- 

 hans were over three times as numerous in the splenic end 

 of the pancreas as elsewhere, and that the part of the organ 

 not in communication with the splenic vein i.e., the extremity 

 of the descending arm contained none. Moreover, each lob- 

 ule in the splenic end of the organ was found to contain an 

 island: a very suggestive fact. The tip of the pancreas, which 

 is almost in contact with the spleen, thus marks the starting- 

 point of the islands; so that trypsinogen begins to enter the 

 splenic vein almost at the hilum. Pancreas and splenic vein 

 being connected by several short venous radicles at about 

 regular intervals, the blood in the vein must become literally 

 saturated with trypsinogen, and its blood be replete with tryp- 

 sin when it reaches the portal vein, during the active stage of 



