- 13 - BUFO. 



17. Venous System. Expose the heart by cutting through the pectoral girdle, 

 open the pericardium and dissect the toad to show the following parts : ventricle ; right 

 and left auricles ; sinus venosus ; inferior vena cava ; hepatic veins ; superior venae cavse ; 

 external jugular, innominate, internal jugular, subscapular, subclavian, musculo-cutaneous, 

 and brachial veins. Also pulmonary veins opening into left auricle. In your drawing 

 indicate also the following nerves: glossopharyngeal (IX): vagus (X); hypoglossal (first 

 spinal nerve) : and brachjaj. 



