BLOOD-VESSELS OF THE HEART VALVES 461 



valve for a short distance along its line of closure are not shown. 

 The A'essels going to the valve from the auricular endocardium 

 form a hedge-like plexus in the base of the cusp and from this 

 plexus delicate vessels pass upward for a distance of about a half 

 of the extent of the valve. No vcvssels were seen in the thin 

 central portion of the valve or in the noduli Arantii. 



Fig. 6 Drawing made upon the photograph of a specimen of human pul- 

 monic valve injected with carmin gelatin. This shows that vessels penetrate 

 the semilunar valves from all sides and reach almost the center of the valve. 



SUMMARY 



The studies may be summarized as follows: 



1. By the injection of carmin-gelatin under pressure of 160- 

 190 mm. Hg. into the coronary arteries, blood-vessels are de- 

 monstrable in the valves of the normal human heart. 



2. The atrio-ventricular valves receive distinct branches from 

 the annular divisions of the coronary arteries. These vessels 

 pass into the valves at the thickened regions above the inser- 

 tion of the chordae tendineae and ramify chiefly along the line 

 of closure of the valves. Arteries, veins and an anastomosing 

 capillary bed are recognizable in these locations. 



