PLATE LIV. 

 FIRST ANTERIOR VIEW OF THE THORAX. 



This plate shows the thorax, with the sternum, costal cartilages, and the anterior 

 extremity of the ribs removed. Great care was taken not to open the pleural sacs and 

 to preserve them hi their normal position. The sternum and ribs were drawn first 

 before removal, and the outline has been traced in white lines over the plate so as to 

 show at a glance the relations of the various structures to the anterior wall of the thorax. 

 The following diagram has been introduced to show the surface marking of the viscera. 



Note on the Pleura. Luschka states that the inner edge of the left pleura diverges 

 normally from the sternum opposite the upper border of the fifth cartilage and at the 

 level of the sternal end of the fifth rib is about half an inch from the edge of the 

 sternum, while at the level of the sternal end of the seventh rib it has receded nearly 

 one and a half inches from the edge of the sternum. St. John Brooks, on the other 

 hand, after a careful investigation, has shown that this is not the case, but that both 

 pleune descend under the cover of the sternum as far as the seventh costal cartilage, 

 and thus in some cases of paracentesis of the pericardium the pleura may be perforated^ 

 though hi others probably the distension of the pericardium has pushed away tho 

 pleura from its loose attachment to the anterior walls. 



