RETZER 



PLATE 1 



FIQ. 1. This shows the second (c) and third (b) parts of the sinovcntricular bundle invading the ventricular mus- 

 culature (a). The upper part of the figure points toward the apex of the heart. Between the cardiac 

 muscle (a) and the bundle (6, c) is seen Curran's sheath. 



FIG. 2. The preterminal part of the bundle is here shown, lying in a dense mass of fibrous tissue. The size of the 

 cells should be compared with the ventricular musculature. 



FIG. 3. This illustrates the terminal part of the sino-ventricular bundle or the Purkinje fibers (6) and a transition to 



the cardiac muscle (a) shown at (ri). C is endocardium. 

 The drawings were all made from the same series. The sections are from an adult pig's septum fixed with Telly- 



sniczky's fluid and stained with hematoxylin and eosin. Enlargement 210 X. 



