160 M. K. KING 



manner at its point of appearance within the left ventricle. The 

 only place to which the fluid could now pass is via the Knoten 

 into the right atrium. In this manner as much fluid could be 

 injected into the Knoten and under as great a pressure as the 

 containing walls would stand. After making an injection it 

 was found best to let the injected specimens stand for three or 

 four days in alcohol or formalin in order to permit the injection 

 fluid to adapt itself to its new quarters. Upon examination of 

 such injected and hardened specimens, the atrial portion of 

 the S.V.S. was found to be imbedded in the atrial musculature 

 and connective tissue to such an extent that considerable dis- 

 secting was necessary before the true results of the injection 

 could be ascertained. 



On exposure of an injected Knoten the latter was found to 

 have the shape so often described previously (fig. 4), i.e., the form 

 of a large nerve ganglion not at all unlike the semilunar ganglion. 

 Its position is very constant and it bears a definite relation to 

 the surrounding structures. The main body of the Knoten rests 

 upon the os cordis from which it is separated only by a thin layer 

 of closely adherent connective tissue fibres. From the main 

 body at least two main branches are given off. One branch 

 extends from 5 to 8 mm. up in a superior direction and is appar- 

 ently in direct connection with the sino-auricular (Kieth and 

 Flack) node. A second main branch extends in the direction 

 of the coronary sinus along which the injection could be fol- 

 lowed for 7-10 mm and at times a smaller branch extends along 

 the left extremity of the os cordis. Smaller inconstant branches 

 along the inferior border of the body of the Knoten approximate 

 the septal musculature, but none were found to pass bej'^ond the 

 fibrous ring. The crus commune in leaving the main body 

 often passes through a sulcus in the os cordis before it divides 

 into the left and right crura. This sulcus was found to be pres- 

 ent in sixty per cent of the hearts examined. Its presence may 

 be due to the bone developing around the crus commune or to 

 the play of the crus upon the developing bone during the move- 

 ment of the heart. In showing a cleaned os cordis to Dr. Meyer 

 he called my attention to the decided smoothness of the sulcus 



