214 THE SALAMANDER 



B. AA. dor so-lumh ales (a.d-lum.). The dorso-lumbar arteries arise 

 from the dorsal aorta at frequent intervals and pass directly dorsal- 

 wards to fuse with the vertebral arteries. In the anterior region of 

 the trunk they are small, but increase in size and importance 

 towards the sacral region. The anterior vessels take some share in 

 supplying the anterior oviducal arteries (q.v.), while the posterior 

 ones may give off small renal arteries to the kidneys, but with these 

 exceptions their main function is to supply the muscles and skin of 

 the back. Not infrequently a small dorso-lumbar artery may be found 

 leaving the proximal portion of the common iliac artery (see also A. 

 vertebralis, p. 204). 



C. A. iliaca communis (a. il.com.). The common iliac artery leaves 

 the dorsal aorta at the level of the sacral vertebra and passes across 

 the dorsum of the pelvis to the leg. Its direction is slightly oblique 

 in a posterior direction parallel with the transverse process of the 

 vertebra and with the ilium. During its course it gives a small twig 

 to the muscles of the back (see above). Just posterior to the hip-joint 

 the common iliac artery breaks up into four branches. It is not easy 

 to distinguish amongst them the familiar 'external' and 'internal' 

 iliac arteries, but it would seem justifiable to regard the branch which 

 passes antero-ventrally across the mesial face of the ilium as the 

 external iliac^ and the other three as representing together the internal 

 iliac. These three branches are, the A. vesicalis^ the A. pudenda^ and 

 the A. ischiadica. 



(a) A. iliaca externa gives off its first branch almost immediately 

 after separating from the iliac artery. 



(i) The A.glutea (a.gl.) or {J) A. femoralis (Osawa) is a medium- 

 sized vessel passing along the thigh antero-dorsal to the A. ischia- 

 dica and the sciatic nerve, and postero-dorsal to the femur. It sup- 

 plies the MM. extensor ilio-tibialis and ilio-femoralis, and then 

 continues down the thigh close to the femur to the knee. Here it 

 gives off a R. cutaneus cruralis posterior^ and then bends round the 

 knee with the N. peroneus to join the R. recurrens of the A. interos- 

 sea externa. It should be noted that the gluteal artery may sometimes 

 leave the A. iliaca communis direct, from the angle between this 

 vessel and the external iliac. 



In the Frog the A. glutea is a branch of the A. ischiadica and is 

 relatively much more limited in distribution, but it should be remem- 

 bered that, in that animal, t\\Q femoral ^LYtCYj — i.e. the ^r^-^;czW vessel 

 — is the main artery of the leg and the A. ischiadica is confined to 

 the thigh, whereas in the Salamander the reverse is the case. The 

 position of the A. glutea posterior to the hip-joint and postero-dorsal 



