1912.] Islets of Langerhans to the Pancreatic Acini. 



83 



part of the 26-day (Experiment 3) grafts. There is a little clear fluid in the tissue about 

 this region, but no evidence of the re-establishinent of the ducts or the escape of 

 pancreatic juice into the bowel can be made out. (Probably some slight connection has 

 been re-established, as the animal's digestion after the first two weeks became so much 

 improved.) 



Microscopic Examination. — The thick, opaque portion resembles that of Experiments 2 

 and 3 referred to above. The shrunken splenic end resembles in some degree the 

 contracted portion of Experiment 3 and the whole of Experiment 4 (26- and 33-day 

 grafts), but there is less increase of duct tissue and considerably less destruction of the 

 acini. A number of large islets are present. These appear normal in every respect, and 

 though their large size and number might lead to the suggestion that new islets had 

 been formed, they are no more in evidence than would be expected in the splenic end 

 after the acinous tissue had shi-unk to perhaps one-half its usual volume. 



Results of Nearly Complete Pancreas Removal. 



These results are to be considered from two points of view : first, and 

 most important, according to the altered appearance of the acini and islets, 

 and second, according to the apparent relation of these appearances to the 

 sugar function of the pancreas. 



It is quite evident from my specimens that, in general, the principal 

 changes which have occurred in the pancreatic remains are the increase of 

 duct and centroacinous tissue, which appears to reach its height in the 

 course of the first few weeks, and an invasion by scar tissue of the acini, 

 and probably of the islets as well. Instead of an interchange of acinous and 

 islet tissue, there is much more a suggestion of a relapsing of islet into duct 

 tissue, and possibly a change of duct to islet. Even in the small fragments 

 which have remained in the animals for several weeks, the acinous cells, 

 though shrunken and considerably altered in their staining reaction, are 

 comparatively easy to recognise. One distinguishes between acinous and 

 islet tissue much more easily than between duct and islet tissue, a fact 

 which might well be expected from a consideration of the embryology of the 

 islets and their constant relation (Laguesse, Bensley) to the ducts in 

 adult life. 



There are present, then, in these specimens, a number of cells which might 

 conceivably be either duct or islet, their grouping suggesting now one and 

 now the other. In all the grafts, the islet cells, that is, the prevailing cells 

 containing the fine slate blue granules demonstrated by the acicl-fuschin 

 technique, the B cells of Lane and Bensley, tend to lose these granules while 

 retaining their mitochondrial filaments, and so resemble strongly the cells of 

 the finer ducts. In the earlier, less cicatrised grafts, such islets are easilv 

 distinguished, and often show only one or two normally stained B cells. In 

 the more scar-like specimens, when the islet cells retain their grouping, and 



