76 DR CHARLES J. PATTEN. 



extensive area of the cardiac surface is intimately related to 

 such abdominal viscera as the stomach and liver (the peri- 

 cardium and diaphragm alone intervening) than is generally 

 supposed. This fact has its practical importance, and may ex- 

 plain more fully the frequent purely functional cardiac derange- 

 ments following temporary distensions or enlargements of the 

 abdominal viscera above mentioned. In certain morbid con- 

 ditions of the heart I frequently found an increased amount of 

 the cardiac surface related to the basal pericardium. In a 

 greatly enlarged heart, which occurred in the Anatomical 

 Department of Trinity College last winter, I noted that not 

 only the basal surface of the ventricles but even a considerable 

 part of the posterior surface rested on the diaphragmatic 

 pericardium. The same thing was present in two hearts in 

 which the right ventricles were markedly dilated. 



So much for the configuration of the human heart. I have 

 considered it advisable to avoid entering into anything like 

 a detailed description of the shape of the organ as observed 

 in specimens specially hardened in situ with formalin. My 

 aim has been chiefly to indicate the extent to which the heart 

 has deviated from the conical mammalian type, as it has come 

 to occupy such a very oblique position iu the thoracic cavity. 



I shall now give a brief description of the configuration of 

 the heart as observed in the full-time human foetus and in a 

 few other mammalian orders. I also append two tables, one 

 containing some heart and chest measurements, the other 

 containing cardiac and thoracic Indices which were worked out 

 from the measurements in Table No. I. 



Heart of human fcdus {fLill-time). — It occupies a large area of 

 the thorax, lying very obliquely. It is placed behind the second, 

 third, fourth, fifth, and sixth costal cartilages of the left side, 

 and behind the second, third, and fourth costal cartilages of the 

 right side. 



The transverse diameter of the heart is greater in proportion 

 than in the adult. The apex is short and rounded ; somewhat 

 deeply placed in the fifth intercostal space of the left side. 

 The right auricle is large, and much of it is seen on the anterior 

 aspect of the heart. 



As in the adult, the pericardium is spread out and attached 



