(b) The cutaneous and the muscular veins, lying under the pectoralis 



muscle, and arising independently from the subclavian vein. They 

 supply the skin and muscles in the region of the arm. There is a 

 second cutaneous vein arising from the abdominal vein and extend- 

 ing on to the skin of the abdomen. Two other small cutaneous 

 veins are seen on the skin of the leg, and another on the skin under 

 the mouth. 



[In the Frog a single musculo-cutaneous vein is seen lying under 

 the pectoralis muscle and extends on to the skin.] 



(c) The abdominal vein, partly visible through the wall of the body, in 



the centre of the rectus-abdominis muscle. 



(d) The brachial vein going to the arm, near which may often be seen 



the white brachial nerve. Endeavour to trace the point of origin 

 of the brachial, muscular, and cutaneous veins (or the brachial and 

 musculo-cutaneous veins in the Frog) as shown in the figures. 



Mylo-hyoid 



Fig. 3. — Muscular System and Vascular System (part) of Xenopus and Rana. 



2. Make an incision in the body wall, slightly to the right side of the 

 abdominal vein, which may now be seen clearly on the inner side of the 

 body wall. Carefully detach this vein from the abdominal wall. 



