LONGITUDINAL SECTIONS OF THE HEART. 333 



carnese and some other slight irregularities, but not the reticulations 

 which exist in the right ventricle. The aorta springs from the base 

 of the ventricle close to the septum. 



A.cardiaca 

 dejctra 



Sinus 

 Vaiso.L\iSe. 



Vaiva 



sem I (u Mart's 



Valva tnciispis 



VenincuLtis 

 sinister 



MzntrituLus 

 dexter 



Fia. 93. — The Doesal Part op the Heart, 



SEEN PKOM THE VeNTEAL ASPECT ; X 1.5. 



Fig. 94. — A Longitudinal Segment of 

 THE Heart, showing the Right Sinus 

 OF Valsalva and Cardiac Artery; 

 xl.5. 



§ 891. Explanation of Fig. 93.— Longitudinal, dextro-sinistral section of the entire 

 heart, seen from the ventral surface. 



Preparation. — This was the heart of a very large male (castrated) cat, a gift from 

 Messrs. MeMn & Badger of Boston, Mass. From the same cat were taken the scapula 

 and humeri, ribs and vertebrae shown in Fig. 4S-i<i, 50, 68-71. 



The heart was not injected or prepared in any special way, excepting hardening in 

 alcohol upon cotton. Hence the cavities are small and the auricles corrugated. When 

 hard, it was divided by a longitudinal dextro-sinistral incision with a large sharp scalpel. 

 The dorsal part is here represented ; the ventral part is a little the thicker. 



The special object of the preparation is to exhibit the relative positions and oonnections 

 of the four great cavities with the auriculo-ventricular valves. In addition, there are 

 shown, (A) the entrance of the prcecntia, which has been longitudinally divided ; (B) the 

 point of entrance or mouth of the postcava, as a dark spot at the beginning of the word ; 

 (C) the aorta and pulmonary artery {A. plm.) ; both are transected, the former just at the 



