432 INTERNAL SECRETION 



pathological alteration may take place at any point in the com- 

 plicated mechanism by which the sugar economy is regulated ; 

 and that a pathological condition of any one of the internal 

 secretory organs associated with the metabolism of the carbo- 

 hydrates, and consequent disturbance of their interrelationships, 

 may give rise to slight glycosuria or even to permanent diabetes. 

 But in these cases a relative insufficiency of the pancreas must 

 also be assumed. 



Such being the state of affairs, the question as to whether 

 anatomically demonstrable changes take place in the pancreas in 

 clinical diabetes, acquires an increased significance. Lesions of 

 the pancreas in clinical diabetes were described before experi- 

 mental pancreatic diabetes had been discovered, and the patho- 

 genetic significance of these lesions was suggested by several 

 authors. The comparative scarcity of instances in which diabetes 

 is accompanied by serious anatomical lesions of the pancreas, and 

 the enormous preponderance of cases in which no anatomical 

 pancreatic lesion is demonstrable, together with the doctrine that 

 serious disease of the pancreas may be unaccompanied by diabetes, 

 are weighty arguments against the pancreas as a constant factor 

 in the pathogenesis of clinical diabetes. 



The changes which are observed in the pancreas in diabetes 

 have recently become a subject of increased interest to anatomico- 

 pathologists. The morphological findings throw some light upon 

 the question as to which tissue element it is which elaborates the 

 pancreatic internal secretion. These, however, will be discussed 

 later. All we need say here is, that recent investigations show 

 that pancreatic lesions of the most varied description, chronic 

 inflammatory and degenerative changes, atrophy and neoplasms, 

 are observed in a comparatively large proportion (according to 

 v. Hansemann about 70 per cent.) of diabetic patients. It is 

 true that these are always cases in which the disease is present 

 in its severest form ; information concerning the slighter aspect 

 of the disease, though its pathogenesis is far more interesting, is 

 very scanty. Negative anatomical findings in the pancreas can- 

 not be regarded as evidence against the pathogenetic significance 

 of this organ : the disturbance of the metabolism of the carbo- 

 hydrates may originate primarily in other links of the functional 

 chain, or the chemistry of the pancreas may be altered without 

 demonstrable morphological changes. 



THE INTERNAL SECRETORY TISSUE ELEMENTS OF 

 THE PANCREAS. 



As in the case of all glands possessing an external secretion, 

 it was at first assumed that the glandular cells of the pancreas 

 were bipolar, that is to say, that both the internal and external 

 secretory functions were performed by the same epithelial cells. 



