6 ELEMENTARY BIOLOGY. [CHAP. 



of two large branches : one (axillary or brachial 

 vein) coming from the antebrachium and manus ; 

 the other (musculo-cutaneous) from the back and 

 head. 



f. 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, ex- 

 ternal 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 alimentary canal above the stomach 

 and also close to the cloaca, and remove the 

 intermediate portion : dissect out the veins 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. 



5. The aortic arches and their branches. 



a. Dissect out the branches of the aortic arches: 

 three on each side. 



