XIII.] 



THE FROG. 



179 



the brain, spinal cord and anterior vertebral 

 region. 



b. Subscapular : returns the blood from the bra- 

 chium and shoulder. These two veins (a. and 

 b.) unite to form the vena innominata. 



c. The musculo-cutaneous vein, receiving the blood 

 of the surface of the head (except the mandi- 

 bular and hyoidean regions) and that of the 

 back of the trunk passes forwards between the 

 internal and external oblique muscles of the 

 abdomen. 



d. The bratfiial vein receives blood from the ante- 

 brachium and manus. 



These (c. and d.) unite to form the subclavian 

 vein. 



e. The veins of the mandibular region and those 

 of the tongue unite into the external jugular 

 vein. 



2 . The system of the inferior cava, formed by the union 

 of the renal, genital and hepatic veins. 



a. The femoral vein from the front of the leg, 

 and 



b. The sciatic vein from the back of the leg, pour 

 their blood into a trunk which lies in the lateral 

 wall of the pelvis and may be termed the pelvic 

 vein; the dorsal end of this becomes 



c. The common iliac vein, which passes to the outer 

 edge of the kidney and is distributed to that 

 organ, whence the blood is carried to the vena 

 cava inferior by the renal veins. 



12 2 



