306 PHYSIOLOGY CHAP. 



internal secretion. He founded this doctrine solely on the fact 

 that the formation of sugar, in the liver is controlled by the 

 nervous system. In 1858 he saw that on puncturing the floor of 

 the rhomboidal sinus near the apex of the calamus scriptorius, 

 such a marked increase of sugar occurs in the blood (liyperylycaemia) 

 that it is eliminated after about an hour, by the kidneys (glycosuria'). 

 He also found that reflex excitation of the bulbar centre suffices 

 to produce the same phenomenon. In fact, stimulation of the 

 central end of the vagus divided between the lung and the head 

 will produce glycosuha. The proof that glycosuria is determined 

 by hyperglycaemia from excessive sugar formation in the liver 

 lies in the fact that diabetic puncture does not produce glycosuria 

 in animals in which the glycogen of the liver has disappeared (by 

 fasting, various intoxications, etc.). 



But the importance at first attributed to the diabetic puncture 

 as discovered by 01. Bernard gradually diminished, as new data 

 came to light. These showed that injury, destruction, or irritation 

 of other parts of the central and peripheral nervous system could 

 produce a more or less transitory glycosuria. Eckhard found 

 that in rabbits lesion of the vermis of the cerebellum induced 

 glycosuria. Schiff recognised the same phenomenon with lesions 

 of various parts of the brain (division of optic thalami, lesions of 

 cerebral or cerebellar peduncles, or of the pons Varolii, complete 

 section of the posterior columns of the cervico-dorsal tract of the 

 cord). Favy saw that glycosuria appeared after section of the 

 bulb and the protracted use of artificial respiration. Lustig and 

 Oddi obtained glycosuria after excision of the caeliac plexus. In 

 our own numerous experiments on the extirpation of more or less 

 extensive and variously localised tracts of the brain or cerebellum, 

 and the total or partial section of the cord at different levels, we 

 have invariably, when the urine was examined, found sugar in the 

 first days after the operation. The same thing occurs (according 

 to Eckhard, Kiilz, Schiff, and others) with the stimulation or 

 simple section of many nerves (particularly the vagi, splanchnics, 

 sciatics). There is thus no circumscribed diabetoyenic centre ; but it 

 may be said that the abnormal excitation of any important part 

 of the central and peripheral nervous system may directly or 

 indirectly provoke glycosuria. 



Both Bernard and Schiff referred the phenomenon of glycosuria 

 consequent on nerve lesions, or the direct or reflex excitation of 

 parts of the nervous system, to the vasomotor disturbances, and 

 resulting active or passive hyperaemia of the liver. This increases 

 the development of hepatic diastase, and therewith the sacchari- 

 fication of the glycogen contained in the hepatic cells. It is also 

 an admissible hypothesis that the liver contains, besides the 

 vasomotor nerves, others which directly influence the metabolic 

 activity of the hepatic cells (and thus regulate the formation of 



