ANATOMY AND EMBRYOLOGY 501 



on the contrary to the pancreas. Of course between the experimental pan- 

 creatic diabetes and the genuine human diabetes there exist considerable dif- 

 ferences. The intensity of the glycosuria is much higher in the latter. 

 In association with Grote and Staehelin, I have pointed to the enormous in- 

 crease in the decomposition of protein and the respiratory exchange of gases 

 in experimental pancreatic diabetes. In genuine human diabetes on the 

 other hand the demand for protein as well as the demand for calories is not 

 increased. The supposition of Benedict and Joslin that the heat production 

 in human diabetes is increased I cannot subscribe to, the reason for which I 

 shall detail later. In consideration of these essential differences 7 have taken 

 position as regards the pathogenesis of human diabetes in a direction contrary 

 to the pancreatocentric; as also v. Noorden, on the ground of his clinical ex- 

 perience and the investigations carried out in his clinic, has upheld the view 

 that in addition to the pancreas, a high value must be ascribed to the chromaf- 

 .fin tissue or the nervous system. 



In addition to the pancreas and the chromaffin tissue, the thyroid gland 

 is certainly of importance in the genesis of many diabetic glycosurias. 



The manner of procedure in the following dissertations must, in order to 

 render possible a condensed exposition of the manifold and complex questions 

 deviate in some points the scheme followed thus far. After some introduc- 

 tory remarks as to the anatomy and embryology of the pancreas the results 

 of the experimental investigation will be given more space than has been the 

 case in the other chapters. Especially will I treat in detail the metabolic 

 disturbances that occur in animals after total extirpation of the pancreas. 

 Also experimental nervous diabetes, so far as it has not already been con- 

 sidered in the chapter on 'the suprarenals, will be dwelt on. In the clinical 

 part, I shall first describe the gross anatomical disturbances of the pancreas 

 simultaneously with the accompanying alterations of metabolism. Then will 

 follow a short exposition of the clinical manifestations of genuine diabetes as 

 far as this is necessary in order to emphasize the points of difference from the 

 changes in metabolism in experimental pancreatic diabetes. The patho- 

 logical anatomy of genuine diabetes mellitus will be treated more in detail, 

 however, including a consideration of the alterations of the pancreas, as well 

 as those of the central nervous system. Only then will I enter into the 

 question as to what role the inner secretion of the pancreas, or the patho- 

 logico-anatomical alterations of the insular apparatus, play in the pathogene- 

 sis of diabetes mellitus. 



Anatomy and Embryology. The pancreas is a long-drawn-out cylindrical 

 organ, situated behind the stomach just in front of the pars lumbalis of the 

 diaphragm. We distinguish from right to left, the broad head lodged in the 

 loop of the duodenum, the neck, the body, and the tail. The head is inti- 

 mately adherent to the loop of the duodenum, while the left end (processus 

 uncinatus) is more movable. On its anterior surface, the pancreas is covered 

 with peritoneum. The length of the organ is about 19-22 cm., the weight, 



