294 PROGRESS OF SCIENCE IN THE CENTURY. 



especial function of maintaining the approximately 

 uniform composition of the blood, arresting super- 

 fluities and poisons, and converting harmful into 

 harmless compounds. Any good text-book * will fur- 

 nish the details. 



An equally good illustration of the increasing rec- 

 ognition of complexity and multiplicity of function 

 is afforded by the pancreas (the sweetbread of rum- 

 inants). This organ, which lies in the (duodenal) 

 fold of the gut succeeding the stomach and pours its 

 secretion into the duodenum, has been recognised — 

 almost since digestion was understood at all — as a 

 very important digestive organ. Its secretion acts 

 powerfully on all the three main kinds of food, — 

 starch, proteids, and fats, — converting starch into 

 sugar, proteids in peptones, and fats into fatty acids 

 and glycerine. But in spite of its importance its 

 digestive secretion can be dispensed with, as has 

 been proved experimentally. 



On the other hand, as Minkowski and von Mering 

 showed, a removal of the pancreas deranges the whole 

 metabolism of the body, and the result is chronic dia- 

 betes or permanent glycosuria, marked by the abun- 

 dance of sugar in the urine. As the amount of sugar 

 can be readily measured, Minkowski was able (1889) 

 to show with some precision the relation between 

 cause and effect, between tampering with the pan- 

 creas and the degree of glycosuria. An additional 

 function of the pancreas was thus discovered, or at 

 all events rendered very probable, f 



These two examples illustrate that line of progress 

 which has revealed an unsuspected complexity and 



* Bunge. Physiological and Pathological Chemistry , 

 Trans. 1890. Lecture XVII. Metabolism in the Liver. 

 t See Bunge. Op. cit.. Lecture XXL, Diabetes Mellitua, 



