PANCREATIC FLUID. 1G7 



affects the time required for the process of solution, is motion. This does 

 not act mechanically, by way of " trituration," as was once supposed ; for food 

 is found to be digested, when inclosed in metallic balls perforated to admit 

 the access of gastric juice to their interior. But it answers the purpose of 

 thoroughly subjecting the whole of the alimentary bolus to the agency of 

 the gastric solvent, by bringing each part successively into contact with the 

 lining membrane of the stomach, from the surface of which the fluid is 

 effused. The removal of the matters already reduced or dissolved, also, has a 

 most important effect in facilitating the solution of the remainder. This 

 removal is due in part to the absorption of the matters in a state of solu- 

 tion, into the bloodvessels of the walls of the stomach; and in part to the 

 successive escape of the reduced portions through the pyloric orifice. The 

 importance of the previous state of minute division and incorporation with 

 aqueous fluid, in promoting the action of the gastric solvent, has been already 

 dwelt on ( 101). 



118. Although the Chyme, or product of gastric digestion, which escapes 

 through the pyloric orifice into the duodenum, contains much azotized mat- 

 ter in a state of actual solution, a considerable proportion of it is still only 

 reduced and mechanically suspended ; and the solution of the latter is con- 

 tinued in the intestinal tube. In the farinaceous part of the food, more- 

 over, no great amount of change has hitherto been effected ; and the sugar 

 which has been generated by the agency of the salivary ferment, is probably 

 absorbed into the bloodvessels nearly as fast as it is formed. In the condi- 

 tion of the fatty matters, no important change is perceptible, except such as 

 results from the solution of the membranes, etc., that inclosed them. Hence 

 we see that the process of Digestion, so far from being completed in the 

 stomach, has only been carried one stage further. Soon after its entrance 

 into the Duodenum, the chyme is subjected to the actions of the Bile, the 

 Pancreatic fluid, and that secretion from the glandulre in the walls of the 

 intestine itself (proceeding from the glands of Brunuer, 114, and Lieber- 

 kiihn), which is known under the name of the " Succus Entericus." Of 

 these, the Pancreatic fluid will be first noticed. The structure of the Pan- 

 creas closely resembles that of the Salivary glands ( 95), for it consists of 

 racemose clusters of secreting follicles, which form the terminations of the 

 ramifying divisions of the duct; each cluster, with its bloodvessels, lym- 

 phatics, nerves, and connecting tissue, forming a lobule ; and the separate 

 lobules being held together by areolar tissue, as well as by the vessels and 

 ducts. The cells of the secreting part of the gland are, according to Lat- 

 schenberger, 1 large, and contain a succulent mass of protoplasm in their 

 interior. If the gland be injected from the duct of Wirsung, a dendritic 

 series of branches are brought into view, which has led various observers 2 to 

 believe that the secretory cells of the pancreas, like those of the liver, are 

 surrounded by extremely fine ducts, which convey the secretion into the 

 larger excretory passages ; but Latschenberger has shown that there are no 

 such independent tubes, the appearance being due to the injection forcing 

 its way not only in the axis of the canal, but through the interspaces be- 

 tween the adjoining cells. The nerves of the Pancreas are derived from the 

 sympathetic system, and terminate, according to Pfluger, in the same way 

 as in the salivary glands, by penetrating the secretory cells. Like both the 

 liver and the salivary glands, the development of the pancreas commences by 



1 Quoted in Briicke's Physiolo^ie, 1874, p. 325. 



2 SeeLangerhans, Inane. Dissert., 1869; Centralblatt, 1870, p. 261 ; and Pfiiiger's 

 Archiv, Band v, p. 203: Giannuzzi, Comptes Eendus, t. Ixviii, 1-869, p. 1280; Savi- 

 otti, 3d. SchuUze's Archiv, Band v, p. 404. 



