METABOLISM, NUTRITION AND DIETETICS 483 



forms or separates a secretion that passes away by special 

 ducts. But it is usual to employ the term only in relation to 

 organs of glandular build, whether provided with ducts or not, 

 It is known that in the case of the liver the internal 

 secretion is more important than the external, for an animal 

 cannot live without its liver, while it may be but little affected 

 by the continuous escape of the bile through a fistulous open- 

 ing. The internal secretions of the pancreas and the kidney 

 are also indispensable. For when the pancreas is excised 

 death follows in many species of animals, and especially in 

 carnivorous animals ; and in man severe and ultimately fatal 

 diabetes is often associated with pancreatic disease, while the 

 mere loss of the pancreatic juice through a fistula does not 

 necessarily shorten life, although the absorption of fat is 

 seriously interfered with. And when the half or two-thirds 

 of one kidney and the whole of the other have been removed 

 from a dog by successive operations (Bradford), death also 

 -ensues, although the quantity both of water and urea excreted 

 by the fragment of renal substance that remains is far 

 above the normal (polyuria). The cause of death in both 

 these cases seems to be a profound disturbance of metabolism, 

 of which the most significant token after extirpation of the 

 pancreas is the increased production of sugar and its appear- 

 ance in the urine, and after interference with the kidneys the 

 increased production of urea. Both in pancreatic diabetes 

 and in experimental polyuria the destruction of proteids is 

 increased. When only one kidney is excised the other hyper- 

 trophies and no ill effects ensue ; nor does diabetes appear 

 after partial removal of the pancreas, so long as a compara- 

 tively small fraction (one quarter or one-fifth) of it is left, 

 even when this remnant is transplanted from its original 

 position and grafted in the peritoneal cavity or indeed under 

 the skin. Although as yet we are entirely ignorant of the 

 :manner in which the kidney* and the pancreas influence the 



* The announcement of Tigerstedt and Bergmann that extracts of the 

 kidney when injected into the veins of an animal cause a rise of arterial 

 blood-pressure, essentially through direct action on the peripheral vaso- 

 motor mechanism, although it may possibly, as they suggest, have some 

 bearing on the rise of pressure and consequent hypertrophy of the heart 

 .associated with certain renal diseases, does not throw ay light on the 

 uela.ion of the kidney to proteid metabolism. 



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