218 FRANKLIN P. MALL 



(fig. 2, B), and ultimately enter the papillary muscles of the 

 left ventricle. It follows, then, that there is one group of super- 

 ficial fibers of the heart which belongs to the left ventricle and 

 one to the right. Since these two muscle groups have been rec- 

 ognized for a very long time and since I have been able to define 

 them with even greater precision through the horns of the vortex, 

 it is well for the sake of easy description to give them specific 

 names. The bundle from the conus and the root of the aorta, 

 — the aortic bulb, — takes a spiral course to the vortex and then 

 enters the septum. It may be termed the bulbo-spiral. The. 

 other group arises from the venous (sinus) end of the embryonic 

 heart and takes a complementary course. It may be termed 

 the sino-spiral bundle. Each group falls into two chief layers, 

 a superficial and a deep, so we have superficial and deep bulbo- 

 spiral bands, and superficial and deep sino-spiral bands. When 

 the modifying term is not used, the superficial band, the band 

 to the vortex, is meant. 



E. H. Weber^'' states expressly that the vortex of the heart is 

 limited exclusively to the left ventricle, while the superficial 

 fibers of the right ventricle do not form a vortex at its apex, but 

 pass into the heart along the anterior longitudinal sulcus as well 

 as at the apex of the right ventricle. They also pass over the 

 posterior longitudinal sulcus to blend with the superficial fibers 

 of the left ventricle. The fibers which pass into the depth are 

 shown in fig. 7, A. A similar figure has been published by C. F. 

 Wolff. 1^ In general this description is correct, but we notice 

 from time to time a vortex of the right ventricle spoken of in 

 the literature. ^^ The examination of a number of well preserved 

 human specimens from which the pericardium and connective 

 tissue have been carefully removed will show definitely that 

 there is a vortex at the tip of the right ventricle as well as at that 

 of the left. This is shown, giving also the course of the main mus- 

 cle bundles, in fig. 2. This figure has been draWn with care and 

 through its interpretation we learn the course of the main muscle 



16 Weber, I.e., vol. 3, p. 146. 



•^ Wolff, I.e., 17S0, Fig.3. TliisfigurewascopiedbyLodor,Anatom.TafeIn, Wei- 

 mar, 1794, Bd. 4, Taf. 114, Fig. 2. 

 1* For example, Krehl, I.e., page 351. 



