THE ADRENAL, SECRETION AND THE HEART. 429 



the right auricle. The experiment in which the cannula was 

 tied in the pulmonary artery, the blood being "allowed to 

 enter the right auricle through insufficiency of the tricuspid," 

 appears to us to further sustain this fact. The heart continued 

 "its rhythmic contractions for eight hours: a period consid- 

 erably in excess of that observed in nutrition through the 

 vessels of Thebesius alone. It was inferred that blood had 

 gained access from the auricle to the coronary veins and had 

 thus aided materially in the nutrition." While this course 

 may have been taken by some of the blood in the experiment, 

 it is obviously not a normal one during life, and the unusual 

 duration of the contractions seems to us to indicate that the 

 blood that penetrated into the right auricle found its way into 

 the Thebesian system via the openings in this auricle, thus 

 approximating as nearly as possible normal conditions. 



The relations between the coronary veins and the Thebe- 

 sian channels are self-evident, excepting, however, a theoretical 

 back-flow from the auricles into the veins suggested by Pratt, 

 which appears to us abnormal; at least it is not compatible 

 with our views of the process. The Thebesian vessels and 

 coronary veins were found to communicate freely on the right 

 side, but not on the left, with the ventricular foramina. The 

 septal foramina were also found to communicate with the 

 coronary vein at the end of the sinus. An interesting feature 

 is the fact that blood passed into the right ventricle flowed 

 freely from a cut vein of the left heart (experiment of April 3, 

 1897). On the other hand, the relations between the coronary 

 arteries and the Thebesian vessels are of a peculiar kind; thus 

 the communication between the left coronary artery and the 

 right ventricle seems as free as that between the same artery 

 and the left ventricle (through the Thebesian channel) is lim- 

 ited. The experiment in which a colored solution was passed 

 into the left coronary artery caused an accumulation of 400 

 cubic centimeters to flow from the right ventricle, while only 

 4 cubic centimeters flowed from the left, sufficiently empha- 

 sizes this fact. Haller, who had observed that injected sub- 

 stances flowed out freely from the surfaces of both ventricles, 

 states that "the passage from the arteries into the cavities of 

 the left side is more difficult." 



