ORGANS OF CIRCULATION. 



189 



limb it extends into that member.^ In 

 the higher vertebrates the subclavian, 

 on entering the fore limb, is known as 

 the axillary artery, ar 

 farther down as the 

 brachial artery, the 

 brachial dividing in 

 the fore arm into ra- 

 dial and ulnar 

 branches which run 

 near the correspond- 

 ing bones. 



With the absorp- 

 tion of the yolk, the 

 omphalomesaraic ar- 

 teries undergo 

 changes. They early 

 lose their direct con- 

 nection with the omphalo- 

 mesaric veins (Fig. 197), 

 while that of the left side 

 disappears without trace, 

 that of the right carrying 

 blood to the yolk, which 

 finds its way to the om- 

 phalomesaraic vein by a 

 system of yolk capillaries. 

 From this persistent ves- 

 sel a branch grows out 



1 Typically the subclavians arise 

 from tlie radix of eitiier side ; but they 

 may have their origin in the adult from 

 the dorsal aorta, or, exceptionally, right 

 and left subclavians may be given off 

 from the radix of one side. 



RA 



Fig. 202. Arterial system of Salamandra, 

 from Wiedersheim. A, allantoic ; Ao, aorta ; 

 ^/, bladder ; (T/, cloaca; Cm, mesenteric; Cr, 

 crural ; Cu, cutaneous ; d, intestine ; E, epigastric ; e, rectum ; H, hepatic ; Hy, 

 hypogastric; /, intestinal; Ik, common iliac; /, liver; M, rectal arteries; m, 

 stomach ; Ov, genital arteries ; P, arteries to pharynx and oesophagus ; R, renal 

 arteries ; RA, radices aortse ; Sc, subclavian. 



