XIII.] THE FROG. 227 



e. The subclavian: follow this outwards; it will 

 be found to be formed mainly by the union 

 of two large branches : one (aodllary or brachial 

 vein) coming from the antebrachium and manus ; 

 the other (^usculo-cutaneous) from the back and 

 head. 



/. The innominate vein is formed by the union of 

 the internal jugular vein, which brings back the 

 blood from the brain and spinal cord, with the 

 subscapular vein returning the blood from the 

 brachium and shoulder. 



g. The superior vena cava {right and left) : this 

 is formed by the union of the subclavian, external 

 jugular and innominate veins on each side : follow 

 it to the heart, where it ends by entering the 

 sinus venosus. 



4. The inferior vena cava and renal portal veins. 



a. Divide the alimentaiy canal above the stomach 

 and also close to the cloaca, and remove the 

 intermediate portion : dissect out the veius con- 

 nected with the kidneys. 



b. The renal portal vein : running from the bifur- 

 cation of the pelvic vein to enter the lower- 

 outer border of the kidney. 



c. The inferior vena cava: the large vein lying 

 between the kidneys and chiefly formed of 

 branches from them, but also getting branches 

 from the generative organs and the liver. 



d. Follow it up to its anterior ending in the 

 sinus venosus. 



15—2 



