260 



ZOOLOGY 



SECT. 



a semilunar valve (2?'.) and by the free end of the longitudinal-valve 

 The bulbus gives off two branches, right and left, each of them 

 divided by two longitudinal partitions into three vessels, an inner 



or anterior, the. carotid 

 trunk (car. tr.\ a middle, 

 the systemic trunk or 

 aortic arch, and an outer 

 or posterior, the pulmo- 

 cutaneous trunk (pul. cu. 

 tr.). The carotid and 

 systemic trunks com- 

 municate separately 

 with the bulbus, the 

 two pulmo-cutaneous 

 trunks communicate 

 with the anterior end of 

 the conus by a single 

 aperture placed just 

 below the free end 

 of the longitudinal 

 A^alve (c'.j. 



After being bound 

 together in the way 

 described for a short 

 the carotid, 

 and pulnlo- 

 cutaneous trunks sepa- 

 rate from one another. 

 The carotid trunk 

 divides into carotid 

 (Figs. 878 and 879, car.} 

 and lingual (lg.) arteries 

 for the supply of the 

 head, the former having 

 at its base a small 

 swelling, the carotid 

 gland (car. gl), consist- 

 ing of a plexus of blood- 

 vessels. The systemic 

 trunks curve round the 

 gullet and unite with 

 one another above it to 

 form the dorsal aorta 

 (d. ao.), from which, or 

 from one of the systemic trunks themselves, the arteries to all 

 parts of the body, except the head, the lungs, and the skin, 

 are given off. The pulmo-cutaneous trunk divides into two, a 



distance, 

 systemic, 



FIG. 879. Rana temporaria. The arterial system, 

 with the heart, lungs, kidneys, and left testis, from 

 the ventral aspect, car. carotid artery ; car. gl. carotid 

 gland ; t. art. conus arteriosus; car. tr. carotid trunk ; 

 ccel. riLts. cceliaco-mesenteric artery ; cu. cutaneous 

 artery ; -<l. ao. dorsal aorta ; du. duodenal artery ; gs. 

 gastric artery ; hp. hepatic artery ; il, jliac artery ; 

 int. intestinal arteries ; kd. kidney ; I. av. left auricle ; 

 (g. -lingual artery ; put. pulmonary artery ; pul. cu. tr. 

 pulmo-cutaneous trunk ; r. au. right auricle; rn. renal 

 arteries ; spl. splenic artery ; syst. tr.. systemic trunk ; 

 sprit, spermatic artery ; ts. testis ; r. ventricle. 



