82 NOTE ON THE CONFIGURATION OF THE HEART. 



Plate VI. 



Heart and pericardium of a full-time male foetus (human). The 

 subject was hardened in formalin. 



Fig. A. — The front wall of the fibrous pericardium has been cut 

 away in order to show the shape of the interior of the sac. The 

 openings of the various vessels belonging to the heart are seen piercing 

 the posterior wall. The expanded basal portion of the pericardium 

 attached to the diaphragm is seen at D. N. = the narrow upper part 

 of the fibrous pericardium. 



Fig. B. — Front view of the heart, showing the correspondence in 

 shape with' the pericardial sac. 



The right auricle is greatly engorged with blood, and so the right 

 border (R.b.) is rounded and somewhat ill-defined. 



m.a. = margo acutus. 

 m.o. =margo obtusus. 

 ^.*S. = anterior surface. 



P. = basal pericardium. 



D. = Diaphragm. 



Y\a, C. — Same heart seen from below, showing the flattened 

 inferior surface of the ventricles {I.S.). 



P.b. — posterior border. 

 m.a. = margo acutus. 

 m.o. = margo obtusus. 



a. — apex. 

 p.s. = part of posterior surface. 



