THE PROBLEM OF IMPULSE CONDUCTION IN THE ATRIUM 135 



MuiR, A. R. (1957) An electron microscope study of the embryology of the intercalated 



disc in the heart of the rabbit. J. Biophys. Biochem. Cytol. 3 : 193-202. 

 Sano, T., Takayama, N. and Shimamoto, T. (1959) Directional difference of conduction 



velocity in the cardiac ventricular syncytium studied by microelectrodes. Circulation 



Research 7 : 262-267. 

 Sjostrand, F. S. and Andersson-Cedergren, E. (1960) The Structure and Function of 



Muscle (ed. by Bourne, G. H.) Vol. 1. Academic Press, New York. 

 Sperelakis, N. and Hoshiko, T. (1960) Possibility of junctional transmission in cardiac 



muscle. Federation Proc. 19 : 108. 

 Sperelakis, N., Hoshiko, T. and Berne, R. M. (1960a) Nonsyncytial nature of cardiac 



muscle: membrane resistance of single cells. Am. J. Physiol. 19 : 531-536. 

 Sperelakis, N., Hoshiko, T., Keller, R. F., Jr. and Berne, R. M. (1960b) Intracellular 



and external recording from frog ventricular fibers during hypertonic perfusion. Am. 



J.Physiol. 198 : 135-140. 

 Trautwein, W. and Dudel, J. (1958) Zum Mechanismus der Membranwirkung des 



Acetylcholin and der Herzmuskelfaser. Arch. ges. Physiol. Pfliiger's 266 : 324-334. 

 Trautvv'ein, W., Kuffler, S. W. and Edwards, C. (1956) Changes in membrane charac- 

 teristics of heart muscle during inhibition. J. Gen. Physiol. 40 : 135-145. 

 Weidmann, S. (1952) The electrical constants of Purkinje fibres. 7. Physiol. {London) 118 : 



348-360. 



