286 SPECIAL HISTOLOGY. 



in the muscular substance of the auricles and ventricles, which 

 is likewise true of Man and other animals. These ganglia are 

 best known in the Frog, in which they are situated, especially 

 in the septum, and at the junction of the auricles with the ven- 

 tricle, and contain apolar and unipolar cells, (Ludwig, Bidder, 

 K. Wagner, myself). The minute fusiform enlargements on 

 the external nervous branches, especially noticed by Lee, are 

 not ganglia, being merely thickenings of the neurilemma. 



[With respect to the particular directions of the muscular 

 fibres of the ventricles, the following remarks may be offered. 

 On the external surface of the ventricles there is a layer, J — 

 V" thick, which, on the left ventricle, runs obliquely down- 

 wards from the pulmonary artery, the anterior longitudinal 

 sulcus and the left transverse sulcus, and in the middle of the 

 wall of the ventricle, descends very abruptly, almost vertically. 

 On the right ventricle, these fibres are oblique only on the 

 conus arteriosus, whilst on the sides and posteriorly they are 

 almost or quite transverse. At the longitudinal sulci, the 

 superficial fibres are continued from one ventricle upon the 

 other, so that a small portion of those of the left ventricle arise 

 from the anterior side of the ostium venosum dextrum and the 

 greater part of those belonging to the right ventricle from the 

 posterior portion of the left ostium venosum. If the fibres of 

 the left ventricle are traced, it will be found, with the excep- 

 tion of those which at the posterior longitudinal sulcus pass upon 

 the right ventricle, that they (fig. 276 a, a', a") run towards 

 the apex of the heart, and there form the well known vortex, 

 and then curve inwards, forming loops ; and are continued as 

 the innermost, for the most part longitudinal, fibres of the 

 cavity of the ventricle, and either ascend as high as the venous 

 openings, or terminate in the posterior papillary muscle. Upon 

 removal of this set of fibres, a thick layer comes into view, in- 

 terposed between its external and internal portions, the fasciculi 

 in which, at first sight, appear to surround the cavity of the 

 ventricle in an oblique and transverse direction, although they 

 seem to arise, without exception, from the ostia venosa, and 

 again to terminate in the same situation, and to describe a 

 figure-of-8 turn, still more distinctly than the external mus- 

 cular layer, as has been clearly shown by Ludwig. I find 



