2o8 THE SALAMANDER 



the anterior arteries above referred to. They are obviously equivalent 

 to the AA. mesentericae posteriores of Osawa. 



The distinction between anterior and posterior mesenteric arteries, 

 as already indicated, must be largely arbitrary, the whole obviously 

 forming a serial complex. It is for this reason that they have been 

 regarded as regions of a 'coeliaco-mesenteric complex'. 



Group 2. Vessels of the Urino-genital System. 



(i) Ovarian or spermatic arteries. The arteries to the gonads are 

 essentially the same in both sexes. They consist of eight or ten fine 

 vessels, i.e. four or five to either side, which arise mesially from the 

 ventral side of the dorsal aorta and pass laterally towards their re- 

 spective gonads through the mesovarium or mesorchium. Those of 

 the right side are more anterior than the corresponding ones of the 

 left owing to the asymmetry of the gonads, but in general they arise 

 from the same section of the aorta as the anterior mesenteric vessels. 

 They pass mesially to the kidneys, and tend to bifurcate very soon 

 after their origin into two parallel but fairly widely separated vessels, 

 which may occasionally bifurcate again. They frequently run in com- 

 pany with a factor of the post-caval vein. The fat-bodies are supplied 

 by branches from these arteries. 



(ii) The renal arteries (a.r.) (AA. renales — Osawa) consist of a 

 number of extremely small vessels which arise from the aorta itself, 

 from the oviducal, ovarian or spermatic arteries, or even from the 

 dorso-lumbar arteries. At the posterior end of the kidney are a 

 pair of much larger superficial renal arteries (a.r.s.) (A. suprarenalis 

 — Osawa) which spread over the ventral face of the kidneys, their 

 ultimate branches being connected with a number of small Mal- 

 pighian bodies around the postero-lateral margin. The small deep 

 renal arteries enter the kidney from the dorsal side. 



(iii) The uterine or oviducal arteries. While these are essentially 

 vessels of the female sex they are also present in the male, and are 

 then distributed to the vestigial Miillerian ducts and ureters, so that 

 they are strictly homologous in the two sexes. They are, however, 

 very much smaller in the male than in the female. The following 

 description is based on the conditions in the female. They arise in 

 three regions, but are not entirely symmetrical on either side. 



(a) The posterior oviducal arteries (a.od.3) arise from a common 

 stem which leaves the dorsal aorta in the midventral line between 

 the posterior lobes of the kidneys, just posterior to the left iliac artery. 

 They are distributed to the expanded posterior end of the oviduct or 

 'uterus', passing along its ventral side and giving off numerous fine 



