TRITON 97 



from the truncus up the 5th visceral arch and joins the lateral 

 dorsal aorta. 



The 6th arterial arch persists as the pulmonary. It also 

 runs up round the pharynx and joins the lateral dorsal aorta, 

 and, just as in Ceratodus, it gives off an artery which runs 

 backwards to the lungs, on each side. The lungs are sym- 

 metrical, and the pulmonary arteries do not twist round the 

 gut as in Ceratodus. The connexion between the pulmonary 

 artery and the lateral dorsal aorta is called the ductus arteriosus, 

 or ductus Botalli. 



The lateral dorsal aortae join one another in the middle line 

 above the gut to form the dorsal aorta. On the way, several 

 arteries are given off : the subclavians to the fore limbs, the 

 cutaneous to the skin, and, near the point of junction, the 

 cceliaco-mesenteric which runs ventrally in the mesentery 

 suspending the gut, and supplies blood to the viscera. The 

 dorsal aorta continues running back, supplying the kidneys 

 on the way, and gives off the two iliac arteries which supply 

 the hind limbs ; thence it runs on into the tail. 



As in Ceratodus, the sinus venosus receives three large 

 veins. These are the paired ductus Cuvieri or superior vena? 

 cavae, and the single inferior vena cava. Each superior vena 

 cava is made up of four principal veins; external jugular (from 

 the ventral regions of the head and tongue) ; internal jugular, 

 corresponding to the anterior cardinal (from the dorsal regions 

 of the head, brain, and skull) ; subclavian, itself made up of 

 the brachial from the fore limb and the cutaneous from the 

 skin ; and the posterior cardinal (anterior portion). 



The inferior vena cava receives the hepatic veins from the 



Fig. 47. — Salamandra : dissection of male seen from the ventral side. 



The nerves are shown on the left and the urinogenital ducts on the right. 

 5a, fifth arterial arch ; aa, anterior abdominal vein ; ab, adrenal bodies ; 

 bp, brachial plexus ; c, cloaca ; ca, carotid arch ; cd, collecting ducts from 

 the excretory portion of the kidney ; da, coeliac artery ; cv, caudal vein ; 

 d, dorsal aorta ; da, ductus arteriosus ; ej, external jugular vein ; /, femoral 

 vein ; ij, internal jugular vein ; k, mesonephric kidney ; pa, pulmonary 

 artery ; pc, posterior cardinal vein ; pv, pelvic vein ; r, rectum ; rp, renal 

 portal vein ; sa, subclavian artery ; sv, subclavian vein ; sy, systemic arch ; 

 syc, sympathetic nerve-chain ; syg, sympathetic ganglion and supra-renal 

 body ; t, testis ; ta, truncus arteriosus ; vci, vena cava inferior ; vcs, vena 

 cava superior ; vd> vas deferens ; ve, vasa efferentia. 



H 



