138 G. K STEWART 



thoracic cofd, although usually the output was still substantial. The re- 

 sult is not modified essentially by varying the level of the cervical section. 

 Even after section as low as the last cervical segment, epinephrin con- 

 tinues to be liberated, and this liberation has all the characters of the 

 normal secretion, and is sustained through the same nerve paths connecting 

 the cord with the suprarenals. In experiments in which the animals were 

 allowed to survive the cervical cord section for some time (up to 13 days), 

 the output never equalled the average ordinary output, although it was 

 often substantial. Strychnin increases markedly the output, by a central 



Fig. 8. Intestine tracings. At 1 and 3, Einger's solution was replaced by 

 indifferent (venous) blood and this at 2 by a suprarenal blood specimen collected in a 

 cat before tying off the head arteries ; at 4, by a suprarenal specimen collected after 

 tying off these arteries. All the blood specimens were diluted with 3 volumes Ringer's 

 solution. From numerous tracings (not reproduced) it was shown that the output of 

 epinephrin was quite as great after the brain and bulb had been eliminated as before, 

 the smaller blood flow per minute being fully compensated by the increased concentration 

 of the epinephrin. (Reduced to one-half.) (After Stewart and Rogoff, Am. J. Physiol.) 



action (on the thoracic cord), after transection of the cervical cord both 

 in acute and survival experiments (Figs. 9 and 10). It is the uppermost 

 thoracic segments which seem to be related to the epinephrin output, and 

 by appropriate section of the dorsal cord lower down the output can be 

 diminished or abolished within the limits of sensitiveness of the methods 

 employed for its detection. There is no definite evidence as to the existence 

 of centers situated higher up in the central nervous system, although from 

 analogy we should expect that impulses coming from above might modify 

 the activity of the spinal center. Theoretically, such impulses might aug- 

 ment or diminish the epinephrin output. It has sometimes been observed 

 that the output after destruction of the cerebral cortex, or section of the 

 brain stem above tbe corpora quadrigemina was increased decidedly beyond 

 the normal range, suggesting that an inhibition had been removed. Elliott 

 (c)(1912) considers that a center concerned in the depletion of the epi- 



