NOTE ON THE CONFIGURATION OF THE HEART. 



79 



In Macacus innuus the heart and thorax are broader than in 

 Cynocephalus babioin. 



2. Anthropoid apes : — 



Two hearts of Hyluhates hainamis. Very similar to that of 

 man both in position and shape. 



The apex is somewhat more pointed in the former. In 

 Hylobates the pericardium is spread out, and is extensively 

 and firmly attached to the diaphragm. The ventricular surface 

 (' inferior or basal '), in relation to the diaphragmatic peri- 

 cardium, is correspondingly extensive, and, as in the heart of 

 man, it is flattened and marked off from the anterior and the 

 posterior (auricular) surfaces by distinct borders. 



The transverse and antero-posterior diameters of the heart of 

 Hylobates are of equal extent. (See cardiac and thoracic indices.) 

 The lateral and antero-posterior diameters of the thorax are also 

 of equal extent. 



I. — Table showing the greatest transverse and antero-posterior 

 Diameters of the Heart and Thorax in different mammalian 

 groups, from which the cardiac and thoracic Indices have 

 been calculated. 



The figures refer to inches and fractions o* an inch. 



