ARTERIAL SYSTEM. 



183 



ing, give rise to the 

 pulmonary, arteries, 

 a narrow ductus 

 Botalli, the lumen 

 of which is some- 

 times obliterated, 

 being usually re- 

 tained. Vessels for 

 the head and occi- 

 pital region are of- 

 ten given off from 

 the roots of the 

 aorta. In the Ba- 

 trachians, which, in 

 consequence of the 

 union of the two 

 posterior branchial 

 arches, possess only 

 three vascular 

 arches, the aortic 

 root is the pro- 

 longation of the 

 middle arch on each 

 side, and gives off 

 the vessels of the 

 scapular region and 

 the anterior ex- 

 tremity, and often, 

 also, on one side an 

 artery to the viscera 

 (mesenteric artery). 

 The postei-ior arch 

 sends off the pul- 

 monary arteries and 

 a strong trunk to 

 the skin of the back, 

 but does not retain 

 its connection with 

 the roots of the 



HI 



Kl 



FIG. 625. u, Urinary and genital apparatus of the left side 

 from a male Salamander, partly diagrammatic. T, testes ; Ve, 

 vasa efferentia ; N, kidney with collecting urinary tubules ; 

 Mg, Mullerian duct ; Wg, Wolffian duct or vas def erens ; Kl, 

 cloaca; Dr, prostate glands, b, Urinary and genital ap- 

 paratus of the left side of a female Salamander without the 

 cloacal part. Ov, Ovary ; N, kidney ; SI, the urinary duct 

 corresponding to the Wolffian duct ; Mg, oviduct or Miil- 

 lerian duct. 



aorta. As in Fishes, 



there is a renal-portal system, as well as an hepatic-portal system. 



