THE SINO-VENTRICULAR SYSTEM 151 



and even Kent after he had demonstrated it in mammals, merely 

 spoke of it as the muscular connection between the auricles and 

 ventricles. No specific name was applied to the system at this 

 time because of the vagueness of the knowledge regarding its 

 size, shape, structure and location. However, after His showed 

 the location and the appearance of the bundle it became neces- 

 sary and proper that the newly-described structure should have 

 a definite name. Hering '05 was the first man to use the term, 

 'The bundle of His,' in honor of its discoverer in mammals. 

 Hering who described the functions of the bundle says in one of 

 his footnotes "His nennt in seiner 1893 erschienen Mitttheilung 

 (Arbeiten aus der medicinischen Klinik zu Leipzig) das den Vor- 

 hof mit der kammer verbindende Blindel das Uebergangsbtindel. 

 Da His dieses Biindel gefunden hat, schlage ich vor, es mit seinem 

 namen zu verbinden und es das, His'sche Uebergangsbtindel zu 

 nennen." A great many workers wishing to establish a more 

 descriptive term in accordance with the B.N. A. have employed 

 the newer terms: the atrio-ventricular (auriculo-ventricular) 

 bundle or the sino- ventricular bundle. Retzer suggested the lat- 

 ter very acceptable term. In his earliest work on the subject 

 Retzer ('04) describes the bundle as "das Verb indungsbiindel," 

 or ''das atrioventricular Muskelblindel," or simply the ' Atrioven- 

 tricularblindel.' In Retzer's ('08) more recent work on the de- 

 velopment of the musculature of the heart, he shows that the bun- 

 dle arises from the sinus and not from the atrium. Because of 

 this fact Retzer suggested the name sino-ventricular instead of 

 atrioventricular bundle. The term 'Reizleitungsysstem,' used 

 so extensively throughout German literature, was first used by 

 Aschoff and Tawara. Since the greater amount of evidence now 

 points to the fact that the sinus bundle is a continuation of the 

 sinus musculature, i.e., that there exists an unbroken strand of 

 modified muscle tis.sue from the sino-auricular node (Keith and 

 Flack) to the termination of the Purkinje fibres, it seems best to 

 use the term, sino-ventricular system. It will be designated by 

 the letters S.V.S. throughout the remainder of this article. 



The most suitable way of studying the relation of loose, elastic 

 sheaths is by the injection method. The application of this 



