4 DK JOSEPH A. BLAKE. 



to four drops of fluid, and the left auricle was only of sufficient 

 size to act as a channel between the pulmonary veins and the 

 foramen ovale. Its appendix was very attenuated. 



The great vessels presented so peculiar an appearance on 

 account of the diminutive size of the ascending aorta (1 milli- 

 metre in diameter), that at first sight there appeared to be a 

 single arterial trunk. 



Closer observation revealed the following arrangement. (The 

 description corresponds with the direction of the blood current.) 



The right ventricle (fig. 1) gave off a large trunk, pulmonary 

 artery, which continued directly (by means of ductus arteriosus) 

 into the descending aorta. The right pulmonary artery was 

 given off from the right aspect, and the left from the dorsal and 

 left aspect of this vessel, where it became ductus arteriosus. 



From the cephalic portions of its bend a trunk was given off 

 (distal portion of arch of aorta), which immediately became 

 dilated, and from the dilatation were given off the left subclavian, 

 left common carotid, and innominate arteries, while a small 

 vessel (the ascending aorta) left its apex, and passing dorsal to 

 the large trunk from the right ventricle, terminated at the 

 cephalic portion of the left ventricle, from which it was separated 

 by a septum of connective tissue about a millimetre in thick- 

 ness. Just before its termination the coronary arteries were 

 given off. 



Examination of the valves revealed the following conditions : 

 The left auriculo-ventricular valve was poorly developed and 

 appeared insufficient. 



The right auriculo-ventricular valve presented two segments, 

 a large right and a small septal. 



The coronary valve was present. The eustachian valve was 

 very rudimentary, consisting of a very narrow fold. 



The foramen ovale was present, but differed essentially from 

 the normal arrangement. Viewed from the interior of the 

 right auricle, it appeared to be completely closed by a thick 

 lunated cushion, the free border of which was ventrally directed. 

 From the left auricle it appeared as a slit-like opening at the 

 bottom of a slight depression. 



It was so arranged that fluids could easily pass from the left 

 to the right, but not from the right to the left auricle. 



