THE PANCREAS. 69 



With the exception of the loose covering given by the meso- 

 colon, the pancreas has no peritoneal coat; neither has it an 

 appropriate tunic, unless we consider as such the larpina of con- 

 densed cellular membrane which envelops it, and sends fp pro- 

 cesses between its lobules, as in the case of the salivary glands in 

 the neck. 



Of the Minute Structure of the Pancreas. This body, like the 

 other glands, which discharge saliva, is of a light gray or pink 

 colour. It consists in lobules of various forms and sizes, united 

 by an intermediate cellular tissue, and having their interstices oc- 

 cupied by numerous blood vessels. These lobules, by a slight 

 maceration, may be separated and resolved into small granulai 

 masses, constituting integral portions of the gland. 



The arteries of the pancreas come principally from the sple- 

 nic, as it cruises along the superior margin. The veins empty 

 into the splenic, and thus, finally, into the vena portarum. It is 

 furnished with nerves from the solar plexus, and has lymphatics. 



The excretory duct of this gland (Ductus Wirsungii) arises, by 

 very fine roots or tubes, from each of the small granular masses. 

 These tubes coalesce into larger ones, which run transversely 

 from the periphery towards the centre of the gland, inclining 

 slightly, at the same time, towards the right. These secondary 

 tubes finally discharge successively into a single one, which runs 

 the whole length of the gland nearly in its middle. The single 

 tube, by these additions, enlarges continually from left to right, 

 being small where it begins at the splenic extremity of the pan- 

 creas, and about the size of a crow-quill at the duodenal. At the 

 latter place, it is joined by the duct of the lesser pancreas, which 

 is derived after the same rule as itself. The pancreatic duct, al- 

 most immediately afterwards, empties into the ductus communis 

 choledochus, or runs at the side of the latter, and makes a dis- 

 tinct opening near it into the duodenum, at the posterior part of 

 the second curvature. 



