THE METABOLISM OF CARBOHYDRATE 



429 



the time being of much dextrose in the urine. If the animal has been 

 starved previous to the puncture, no such result follows. There is 

 therefore, supposed to be a " centre " in this region of the medulla 

 through which the glycogenic function of the liver is controlled. The 

 result has been attributed by some authorities to the disturbance of 

 the circulatory conditions of the liver, owing to interference with the 

 vaso-motor centre. Such circulatory disturbance possibly does play 



30 60 90 120 150 180 210 240 270 300 



Minutes. 



Fia. 217. CURVES SHOWING THE RELATIONSHIP BETWEEN THE CONCENTRATION OF 

 SUGAR IK ARTERIAL BLOOD, THE CONCENTRATION OF THE URINE, AND THE RATE 

 OF URINE FORMATION, FOLLOWING STIMULATION OF THE SPLANCHNIC NERVE. 

 (MacLeod.) 



a part, but it is more generally held that there exists a true glycogenic 

 centre apart from the vaso-motor centre. To this centre run afferent, 

 and from it efferent paths. The afferent paths are not fully eluci- 

 dated. Interference with other parts of the brain and nervous 

 system may induce glycosuria. Fright causes glycosuria in a cat. 

 If the vagus nerve be cut in the neck, stimulation of the central end 

 produces glycosuria. This experiment has been interpreted as showing 

 that the vagus contains afferent fibres to the glycogenic centre. It 

 seems more probable that the glycosuria results from the asphyxial 



