30 Society for Experimental Biology and Medicine. 



delivered into the trachea. By such administration it has been 

 shown by Hirsch that the blood remains arterial even after the 

 respiratory movements have been inhibited by curare. When the 

 cervical spinal cord is stimulated, and especially when it is cut, the 

 respiratory movements are very considerably interfered with so that 

 a partial asphyxia is produced which may be the cause of the 

 hyperglycemia. 



The fact that stimulation of the cervical cord causes glycosuria 

 cannot therefore be taken as a proof of the existence of efferent 

 fibers which control the glycogenic function of the liver. Dyspnea 

 may be the cause of the hyperglycemia in these cases. 1 



Regarding the other evidence, which is supposed to point to 

 the existence of such fibers, we would point out that in all the ex- 

 periments on which it is based (viz., cutting the splanchnics, or 

 sympathetic chain, or certain nerve roots, or the spinal cord, there 

 must have been induced by the operation, a great fall of blood 

 pressure which, in the cases of dogs with vagal glycosuria, Dolley 

 and the writer have shown usually to cause a marked depression 

 in the reducing power of the urine (loc. cit.). 



Conclusion. — When every precaution is taken to prevent as- 

 phyxia we have been unable, so far, to demonstrate the existence 

 of any efferent fibers whose stimulation causes hyperglycemia. 



1 Underhill ( The Journ. of Biol. Chem., 1905, i, p. 113), explains the hyperglyce- 

 mia produced by the administration of certain drugs on the same basis, viz., that they 

 produce dyspnea by an action on the respiratory center. 



