196 E. G. HOSKIKS 



that are published in illustration of the article as compared with those that 

 the writer has obtained suggest that either the vena cava itself might have 

 been materially occluded in the process of shutting off the suprarenal cir- 

 culation, or that the ligature included a considerable number of splanchnic 

 fibers, thus leading to a sharp fall of arterial pressure. 



Young and Lehman repeated these occlusion experiments, using dogs 

 as subjects. The ligatures in their investigations were kept in place 

 for periods of ten to thirty minutes. Very little fall of blood-pressure was 

 observed and any such occurred very gradually. Upon releasing the liga- 

 tures in three of their eight experiments a decided rise of pressure oc- 

 curred; in two a slight rise; and in three no change. Young, in a repeti- 

 tion of the experiment, observed no significant fall of pressure for hours 

 after tying off the glands. 



In a discussion of the work of Strehl and Weiss, Kahn (1909) pointed 

 out that they had failed to recognize an important source of error in their 

 experiments. The mere irritation of the peritoneum, such as was in- 

 volved in the manipulations incident to ligating the veins from the supra- 

 renal, is capable of evoking depressor reflexes with resultant reactions 

 quite as extensive as those figures by Strehl and Weiss. In Kahn's paper 

 a tracing is reproduced which shows a clean-cut fall of blood-pressure fol- 

 lowing ligation of the suprarenal vein in an animal from which both 

 suprarenals had previously been extirpated. In only one instance in many 

 experiments did this investigator see a fall of pressure that could properly 

 be ascribed to occlusion of the venous outflow from the suprarenal gland. 



Biedl reported that after removal of the suprarenals from an ex- 

 traperitoneal situation to which they had been transposed, there was 

 a fall of blood-pressure lasting fifteen to thirty minutes, but at the end 

 of that time the blood-pressure gradually increased and by the next day had 

 regained a normal level. In animals in which particular care was taken 

 to avoid too profound anesthesia and operative severity, blood-pressure 

 usually was noTmal for two or three days after suprarenal extirpation. 



In 1912 the problem was again investigated by Hoskins and McClure. 

 Eleven dogs served as subjects. The effects of anesthetics upon gland 

 discharge being unknown, a variety of substances was used: urethane, 

 urethane and ether, ether alone, and chloroform. The method of procedure 

 in 9 cases was essentially that of Strehl and Weiss, After inserting a 

 cannula in the carotid artery the abdomen was opened by a median in- 

 cision and, while the viscera were protected by warm towels, the ends of 

 strong ligatures were inserted through the body-wall in such a manner 

 that, by subsequent traction, the circulation of each suprarenal could be 

 cut off. The abdomen was then closed. After waiting for some time for 

 the immediate effects of the operation to pass off, recording of arterial 

 pressure was begun. After blood-pressure had been maintained for some 

 minutes at a constant level, one ligature was drawn tight then, after a 



