422 THE DYNAMICS OF CARDIAC ACTION. 



heart. Some of these foramina are minute depressions in the 

 walls of the heart, presenting a closed extremity." 1 This in- 

 formation would afford but little light could we not supple- 

 ment it with an excellent paper by F. H. Pratt, 2 in which the 

 nutrition of the heart through the vessels of Thebesius and 

 the coronary veins is studied. How much we are indebted to 

 the author for his investigations is suggested by the following 

 remarks: "So far as I have been able to determine, no experi- 

 mental physiological work has ever before been done on the 

 vessels of Thebesius; all opinion regarding their functional 

 importance has rested upon the assumption that they only 

 serve as veins, conveying a part of the venous blood from the 

 coronary capillaries through the foramina Thebesii into the 

 cavities of the heart." 



After referring to the labors of Thebesius (1708), Vieus- 

 sens (1757), Haller (1786), and Abernethy (1798), the author 

 reviews the more modern investigations of Bochdalek, 3 which 

 led to the conclusion "that the greater number of the small 

 openings on the inner surface of the right as well as the left 

 auricle, which from early times have borne the name of 

 foramina Thebesii, represent the mouths of little veins that, 

 often uniting into larger vessels, course with many branches 

 through the auricular walls.' 7 Langer's researches 4 on the 

 foramina of the human heart are next analyzed. "With the 

 aid of the blow-pipe, and by means of a watery injection-mass 

 colored with Berlin blue, he demonstrated these foramina in 

 all the cavities of the heart. He succeeded in injecting the 

 vessels of Thebesius not only from the coronary vessels, but 

 from the endocardial surfaces as well. Bochdalek's observa- 

 tions regarding the presence in both auricles of foramina 

 Thebesii were thus confirmed, and the fact of a communication 

 between the coronary vessels and each of the four cavities of 

 the heart was thoroughly established. The foramina which 

 Langer found on the endocardial surfaces of both ventricles 

 were similar to those in the auricles, but much smaller. They 



i All italics are our own. 



3 F. H. Pratt: American Journal of Physiology, vol. 1, p. 86, 1898. 

 s Bochdalek: Archiv fur Anat. u. Phys. u. wiss. Med., Leipzig, p. 314, 1868. 

 Langer: Sitzb. der k. Akad. der Wissensch. zu Wien, 1880, Bd. Ixxxii. 3 

 Abth., p. 2u. 



