340 R. R. BENSLEY 



Thus, in dogs as well as in guinea pigs my counts offer no sup- 

 port to the idea that after several days' withdrawal of food the 

 number and size of islets in the pancreas are increased. 



THE RELATION OF THE ISLETS OF LANGERHANS TO THE DUCTS 



AND ACINI OF THE PANCREAS 



The majority of workers are agreed that the islets when fully 

 formed have no connection with the ducts, although many admit 

 that they are formed in part from the duct system. The con- 

 nection with the duct system is, however, a logical necessity for 

 those who maintain that islets and acini are interchangeable 

 structures, while, on the other hand, the proof that they were 

 separate from the ducts would be a strong argument in favor 

 of their having a function distinct from that of the rest of the 

 pancreas. It is not surprising, therefore, that this question has 

 been the subject of considerable discussion. A full account of 

 the observations which have been made and of the views which 

 have been expressed concerning it, will be found in Laguesse's 

 summary of the literature ('06-'08). It will suffice here to point 

 out that there is evidence of a reaction against the view of inde- 

 pendence not only in the observations recorded by those who 

 believe that islets may be transformed into acini and acini into 

 islets, but also in the form of actual demonstrations of continuity. 

 Laguesse, perhaps, takes the most advanced stand on this question 

 for he says that direct connections with the ducts are the rule 

 rather than an occasional exception, and that many islets may 

 have several such connections. Laguesse ('10) has also demon- 

 strated in the clearest way the continuity of islet tissue and acinus 

 tissue as well as the connection between intralobular ducts and 

 islets, supporting his descriptions by drawings of series of sections 

 which show unmistakably direct contact of islet cells and acinus 

 cells without any intervening connective tissue septum. 



Weichselbaum and Kyrle ('09), also, have observed islets in con- 

 nection with the ducts in the human pancreas, particularly in 

 young subjects and the general purport of Helly's work ('06) on 

 the histogenesis of the pancreas is in the same direction. These 

 authors, however, do not express clearly their views as to the fre- 



