342 THE METABOLISM OF THE CARBOHYDRATES 



puncture, is evidence of this. Moreover, the centre can be excited 

 by the stimulation of afferent nerve fibres. It is a true reflex 

 centre. The afferent fibres run in most of the sensory nerves, and 

 have been exhaustively studied in the vagus nerve of the rabbit, 

 especially by C. Eckhard( 17 ). This worker found that by merely 

 cutting one vagus in the neck, a transitory glycosuria lasting a few 

 hours was produced. After the urine had become sugar-free, the 

 central end of the cut nerve was stimulated electrically, off and on, 

 for three-quarters of an hour, whereby the urine became glycosuric. 

 The wound was then closed and the rabbit placed back in its cage. 

 Next morning, the urine had become sugar-free. The nerve was 

 again stimulated and sugar again appeared in the urine, and so 

 on for several days. This experiment was successful only on well- 

 fed animals. The glycosuria which appeared on merely cutting 

 the nerve had doubtless been due to irritation. Cutting the 

 sciatic nerve and irritation of the cardiac depressor nerve in the 

 rabbit similarly tends to induce glycosuria. 



Several clinical cases are reported where severe neuralgias (of 

 facial and sciatic nerves) and the pressure of tumours on nerves 

 (vagus) existed in patients exhibiting glycosuria. 



The following table of observations by Dolley and the author 

 illustrates this form of experimental glycosuria. 



TABLE III 



So far, then, we see that there must be a centre in the medulla, 

 stimulation of which causes an increased production of sugar in 

 the organism, with a consequent hyperglycaemia and glycosuria ; 



