THE LIVER AND PANCREAS 259 



to pass out of the stomach the pancreas becomes active. In this 

 connection, however, it is desirable to remember that according 

 to some observers a starved dog will actively secrete pancreatic 

 juice for twenty minutes every two hours. The continuous 

 secretion of the gland in herbivora is provided for by all the lobes 

 not being active at the same time. In the ox the amount of juice 

 secreted is about 265 grammes (9 ounces) per hour, in the horse 

 it is much the same, in the sheep 7 to 8 grammes (J to | ounce), 

 pig about 5 to 15 grammes (J to J ounce) per hour, and in the 

 dog still less, 2 to 3 grammes. There is no necessary ratio 

 between the size of the animal, the weight of the gland, and the 

 amount of pancreatic fluid secreted ; carnivora secrete relatively 

 more than herbivora. 



The pressure under which the pancreatic juice is secreted is 

 low ; it is said to be equal to 18 mm. (067 inch) of mercury, 

 which is very little greater than that of the bile. 



Pancreatic Diabetes.* — If the pancreas of a dog be completely 

 removed, there is a disappearance of all glycogen from the tissues, 

 sugar appears in the urine within twenty-four hours, and the 

 animal dies in the course of a month or less with diabetes, since 

 the power of oxidising dextrose is lost. The dextrose consequently 

 accumulates in the blood, and is separated by the kidneys. In 

 addition to there being sugar in the urine, there is also an increase 

 in the amount of fluid produced and an excess of urea ; conse- 

 quently there is intense thirst, and this is associated with a large 

 appetite in spite of which the animal wastes. If the depancreated 

 animal be placed on a purely proteid diet, no difference occurs 

 in the amount of sugar excreted ; even if no food be given sugar 

 is still formed. If the removal of the gland is incomplete, glyco- 

 suria still occurs, but it will vary in intensity from fatal to 

 transient effects, depending upon the amount of pancreas left 

 l>ehind ; in fact, it is possible by experience to leave behind just 

 sufficient (one-fourth to one-fifth) of the gland to prevent diabetes 

 arising. In any case, fatal results may be avoided by grafting 

 portions of pancreas beneath the skin, the presence of these 

 preventing diabetes. This proves that the prevention of 

 glycosuria does not depend on the pancreatic juice. 



Regulation of the Sugar Supply. — Throughout these remarks 

 on the glycogen question, we have assumed that the view 

 originally put forward by Bernard is correct — namely, that the 

 sugar resulting from the- conversion of carbohydrates in the 

 digestive canal is stored in the liver and muscles as glycogen, 

 while a definite proportion of sugar remains in circulation. The 

 chief opponent to this theory is Pavy, who believes that glycogen 



* To avoid repetition, this matter should be read in conjunction with the 

 remarks on Glycogen, p. 246. - 



