=Virchow Method.= The heart is rotated toward the left side of the cadaver so as to bring the venæ cavæ into view, and is held by the index-finger and thumb of left hand. An incision is then made in the wall of the right auricle, beginning midway between the two cavæ and extending downward as far as the right auriculoventricular ring, in the direction of the right ventricular ridge. The tricuspid is examined from above. The tricuspid ring may be left uncut and an incision made in the ventricle-wall, beginning just below the valve and extending downward along the right ventricular ridge to the septum, or the incision may be carried down in the same line passing through the tricuspid ring. The long narrow-bladed knife or the enterotome is introduced into the right ventricle and an incision made from the middle of the first incision, just above the insertion of the anterior papillary muscle, through the pulmonary orifice into the pulmonary artery, passing between the two anterior leaflets of the pulmonary valve. The heart is now drawn up on the right edge of the ribs so that the left ventricular border presents uppermost. The left auricle is then opened by an incision beginning in, or just below, the lowermost pulmonary vein and extended in the direction of the left ventricular ridge as far as the auriculoventricular ring. Beginning just below the ring an incision is made through the entire length of the left ventricular ridge as far as the apex and to the septum, which lies usually beyond the apex. A second incision is then made in the left ventricle from the apex, extending through the anterior ventricular wall close to the septum, parallel to the descending branch of the anterior coronary artery and about 1 cm. from it, and passing through the aortic opening between the anterior and the right posterior cusps. This is the more easily accomplished if the pulmonary artery has been dissected away from the aorta, so that the incision can be carried well over to the right. (See Fig. 41.) As the chambers of the heart are opened the contents should be inspected, clots removed, and the valvular orifices examined from the upper side. The coronary arteries are then opened with the fine probe-pointed scissors. When the heart has been removed from the body it may be opened on the board by following the method as given above. The heart is held very conveniently for the Virchow incisions by putting the four fingers of the left hand beneath it and the thumb on the anterior surface; complete pronation puts the heart in the position for opening the right side; complete supination gives the position for opening the left side. [Illustration: FIG. 40.—Section of right auricle and ventricle, according to Nauwerck.] [Illustration: FIG. 41.—Incision for opening of aortic ring; same for all methods described in text. (After Nauwerck.)]