50 DISSECTION OF THE DOG 



costaHs) is convex and is crossed obliquely by a furrow, the ventral 

 longitudinal sulcus (sulcus longitudinalis ventralis), which commences at the 

 root of the pulmonary artery and extends as far as the right border, ihe 

 diaphragmatic surface (facies diaphragmatica) differs in being not so convex 



vena azygos \ 



Vena cava cranialis 



a. suhclavia sinistra 



--a. IracJiio-cepJtalica 



a. pttlmonalis ^^ 



vz. pulmonaliS^ 



Auricula dextra 



Vena cava caudalis^ 



Ay ex COld^S 



Fig. 21. — Outline of the heart as seen from the right. 



and of much smaller extent. It is traversed by a dorsal longitudinal sulcus 

 (sulcus longitudinalis dorsalis), which begins at the coronary sulcus opposite 

 the terminal part of the caudal vena cava, and ends by joining the ventral 

 longitudinal sulcus at the right border of the heart. The two grooves indicate 

 the position of the septum between the two ventricles. 



The borders of the heart differ considerably. The right is the longer, the 



