160 G. K STEWART 



hyperglycemia. For the innervation of other organs, especially the liver, 

 is thus crippled. A negative result obtained after double splanchnotomy 

 could have no value in this connection. 5. In experiments on piqure 

 the floor of the fourth ventricle should be exposed under local anes- 

 thesia. 



It has been shown by Stewart and Rogoff (g) (fc) O) (1917-18, 1920) 

 that, when the above mentioned conditions are fulfilled, the experimental 

 hyperglycemias under discussion are well obtained in the absence of epi- 

 nephrin discharge from the suprarenals. The so-called epinephrin hypothe- 

 sis of these hyperglycemias should, therefore, be abandoned. Whatever the 

 mechanism of their production may be, the suprarenal bodies are not 

 essentially concerned. It has not been proved that the epinephrin liberated 

 from the suprarenals even sensibly facilitates the production of any of the 

 hyperglycemias, although some observers (Macleod and Pearce) believe 

 they have obtained a certain amount of evidence that this may be the case. 

 If a slight influence of this kind really existed it would be very difficult in 

 such observations to disentangle it from the variations due to conditions 

 which cannot be controlled. This is the main reason for the contradictory 

 statements in the literature in regard to the existence of the so-called emo- 

 tional hyperglycemia. Some writers (Shaffer, e.g.) have convinced them- 

 selves that emotional hyperglycemia is so easily produced in the ordinary 

 laboratory animals that it is impossible to obtain "normal" sugar percen- 

 tages unless great precautions are adopted to prevent excitement. Others 

 (Ross and ^IcGuigaii) have found it difficult to convince themselves that a 

 real emotional hyperglycemia exists. A survey of the available data 

 (Stewart and Rogoff (</), 1917) indicates that in any case there is a funda- 

 mental distinction between the hyperglycemia associated with asphyxia, 

 anesthesia or piqure, which is well established and easily verifiable, and 

 "emotional hyperglycemia," the existence of which is asserted by some 

 authors on the basis of small and inconstant differences in the blood sugar 

 content, which other writers consider to fall within the limits of variation 

 of the normal. There is no evidence that "emotional hyperglycemia," if it 

 exists, is at all related to the epinephrin discharge from the suprarenals. 

 The possibility may be admitted that different species of animals, perhaps 

 different individuals of the same species, may vary in their susceptibility to 

 emotional excitement as regards changes in the blood sugar content. If this 

 were so, man might be expected to be more susceptible than lower animals. 

 Cannon, Sholl and Wright saw glycosuria regularly in cats as a result 

 of emotional excitement, and Cannon (a) (with Smillie and with Fiske) 

 found it in some of the students of a class subjected to the stress of an 

 examination, and in football players. 



Several of the writers on the problem of the possibility of producing 

 experimental hyperglycemia (and glycosuria) after removal of the supra- 

 renals have raised the question of the ability of the liver to form or to 



