260 A MANUAL OF ANATOMY. 



1 893 with the camera (see " Relations of the Heart and 

 Lungs to the Anterior Chest Wall," as determined by 

 composite photographs, published in the Medical Journal 

 of November n and December 9, 1893) and by compari- 

 son of the conflicting statements of the various authors. 



(1) Base of Heart. A line crossing the sternum ob- 

 liquely from the upper margin of the third right to the 

 lower border of the second left costal cartilage, an inch 

 and a half from the median line on each side. 



(2) Apex. In the fifth space near the upper margin of 

 the sixth costal cartilage, two and a half inches to the left 

 of the median line. 



(3) Right Border. From the right end of the base 

 curved slightly outward to reach a point an inch and three- 

 quarters from the right of the middle line over the fourth 

 cartilage and ending at the centre of the fifth cartilage an 

 inch from the mid-sternal line. 



(4) Left Border. From the left end of the base with a con- 

 vexity outward to the apex. It reaches its greatest distance 

 (three inches) from the sternal centre over the fourth space. 



(5) Lower Border. A line curved downward at its 

 beginning (at the lower extremity of the right border) and 

 ending (at the apex), and slightly convex upward in its 

 centre as it crosses the middle of the ensiform. 



(6) The Area of Heart Dullness. A quadrilateral area to 

 the left of the median line and below the upper border of the 

 fifth cartilage, nearly two inches in vertical and an inch and 

 a half in extreme lateral measurements. See anterior bor- 

 der of left lung below. 



(7) The Auricles. The Right: An "ear-shaped" area 

 facing to the left, covering the first inch of the third right 

 space and cartilage with the portion of the sternum adjacent 

 to the latter. Its long axis measures about two inches and 



