FATE OF THE FOOD ABSORBED 389 



urine (glycosuria). This condition is seen when the posterior 

 part of the floor of the fourth ventricle in a rabbit is punctured. 

 If glycogen be abundant in the liver, glycosuria results, 

 the stimulation of the nervous system producing a too rapid 

 conversion of the glycogen. 



Another way in which sugar may be made to appear in the 

 urine is by injecting phloridzin. Under the influence of this 

 drug the sugar in the blood is not increased. It must be 

 concluded that it acts by causing the kidneys to excrete glucose 

 too rapidly, so that it is not available for the tissues. But 

 even when carbohydrates are withheld and cleared out of 

 the body, phloridzin causes glycosuria. Hence the kidneys 

 must be made to form glucose from the protein of the blood 

 plasma. 



The injection of large doses of extract of the suprarenal 

 bodies causes a glycosuria with an increase of sugar in the 

 blood ; but so far it is not known whether the condition is- 

 one of increased production or of diminished utilisation of sugar 

 (p. 406). 



Removal of the pancreas also causes glycsemia and glycosuria 

 (p. 410). 



2. Relation to Fats. Although the fats are not carried 

 directly to the liver, as are proteins and carbohydrates, they 

 are stored in large amounts in the liver of some animals e.g. 

 the cod among fishes and the cat among mammals. Animals 

 which have little power of storing fat throughout the muscles 

 and other tissues generally, seem to have a marked capacity 

 for accumulating it in the liver. Even in starvation the fats 

 do not disappear from the liver, and throughout all conditions 

 of life a fairly constant amount of lecithin a phosphorus and 

 nitrogen containing fat (see p. 76) is present in the liver 

 cells. Lecithin, in the yolk of the egg, is an intermediate 

 stage in the formation of the more complex nucleins of living 

 cells, and the formation of lecithin in the liver by the synthesis 

 of glycerin, fatty acids, phosphoric acid, and cholin is probably 

 a first step in the construction of these nucleins. If this be 

 so, the fat of the liver must play an important part in retaining 

 and fixing phosphorus in the body. 



3. Relation to Proteins. Along with the intestinal wall, 

 the liver regulates the supply of proteins to the body. A 



