168 FRANCIS M. POTTENGER 



junction (EJliott, 1905). That the action is not directly upon the cells is 

 inferred according to Macleod from the fact that epinephrin is "incapable 

 of acting on tissues which are devoid of sympathetic nerve fibers, and is 

 also inactive on those, tissues in the embryo which have not yet received 

 any nerve supply/' Recent experiments by Hartman (1917), however, 

 show that the action of epinephrin in the control of the blood vessels of 

 the body may be exerted either in the dorsal root or sympathetic ganglia, as 

 will be discussed later. 



Control of Suprarenal Secretion. Biedl (a) and Dreyer have shown 

 that stimulation of the sympathetic fibers to the suprarenal glands causes an 

 augmented secretion of epinephrin. .From this fact the inference follows 

 that any condition leading to generalized discharge through the sympa- 

 thetic system leads to a similar effect. Several investigators, and espe- 

 cially Cannon and his coworkers, have adduced positive evidence that the 

 emotions, pain, and asphyxia, all of which lead to generalized sympathetic 

 discharge, cause an enhanced discharge of epinephrin. Stewart maintains, 

 however, that none of the evidence so far offered is adequate to deter- 

 mine the matter. It is by such "after discharge" of epinephrin that Can- 

 non (/;) explains the prolonged bodily reaction to emotions after all super- 

 ficial evidence of the operation of the exciting cause has disappeared. The 

 writer has called attention (1916, 1918) to the fact that an analysis of 

 the syndrome of toxemia, as expressed in the peripheral tissues, shows its 

 manifestations to be a result of general sympathetic stimulation. We are 

 justified in assuming, therefore, that toxemia stimulates the suprarenals 

 and causes them to produce an increased amount of secretion, which aug- 

 ments and prolongs the effect of the nerve stimulus; and further, that 

 severe or chronic infections may stimulate and exhaust the suprarenals. 



The question of inhibition of action in the suprarenal gland is one that 

 has interested physiologists and clinicians for a long time. Heretofore 

 nothing definite has been known, but Cannon (1920), as a result of recent 

 investigation, states that stimulation of the afferent vagus fibers causes 

 inhibition of the suprarenal medulla; while stimulation of the sensory 

 somatic fibers resulte in increased suprarenal secretion. This is a very 

 important contribution. 



Relation of the Suprarenals to Glycosuria. Another interrelationship 

 between the sympathetics and suprarenal secretion is shown in the produc- 

 tion of glycosuria, so-called "nervous diabetes," following such conditions 

 as grief, fright, a,nd other forms of sudden and severe emotion. It has 

 long been a clinically recognized fact that diabetics stand emotional stress 

 poorly. The writer recalls a diabetic who had become sugar-free. He was 

 playing croquet when a ball bounced and struck him on the chin. He was 

 frightened and suffered some pain, and immediately had a return of sugar. 

 Cannon cites the experiments of Bohm and Hoffman, who reported in 1878 

 that cats which were subjected to pain showed glycosuria. These cats 



