The differences in the blood supply of the right and left ventricles have not been sufficiently emphasized. The reason for this probably lies in the fact that most of the recent contributions to the knowledge concerning the coronary circulation have been acquired from a study of cleared specimens of the heart. These preparations are seldom entirely transparent. Consequently, in the thicker portions, such as the left ventricle, the arterial tree is incompletely shown. The roentgen method also has been used by many observers. This method is likely to give misleading pictures, owing to the fact that the interventricular septum is crescent-shaped, which makes it difficult to distinguish the vessels of the septum from those of the cardiac wall.
On the contrary, specimens prepared by the celluloid corrosion method are better suited for a comparison of the blood supply of the two ventricles. If casts of the cavities of the heart,