AND CIRCULATION IN FI3HES. igi 



inufcles of the back and lateral parts form a trunk refenibling 

 our right fubdcwlan vein; to which thc intei^nal jfigttlar ^2> 

 and exterml jngular 34 are (oon added. A little farther in, 

 the rioht vem cavci hepatica 31, tcrminates; andthis, at 32^, 

 3s joined to the left vena cava hepatica. The communicating 

 canal alfo receives the blood from a middle lobe of theliver; 

 that orgnn being difided into three lobes. The two cavae 35, 

 at Jaft meetj and after receiving tlie coromrij veins 37 of the 

 heart, difcharge tbemfelves through a round iiolc with rifing 

 cdges into the back part of the auricJe of the hcart» 



i8« Within the external jugular veins, and at the termi- 

 nation of the internal jugulars, I obferve a pair ofvalves, like 

 to thofe in the veins of the human fubjed. At the termina» 

 tion of the renal veine and Jarge branches of the hepatic veins 

 we find lingle membranes iixed by threads from their edges, 

 refembling tlie valve of the coronary veinof our heartj and 

 at the termination of the othcr iarge veins, efpecially near the 

 heart, "we not only find the orifices contrac^ed, but doublings 

 at their edges, which have fo far the effecfl of valves, even 

 in the dead body, that we cannot fill completejy all the veins 

 by throwing an injediion in at one of their branches; and bct- 

 ween the auricle and ventricle, valves are interpofed, wliich 

 perforii) their olBce with great accuracy. 



Sea V. 



29. Affer (racing the blood m its courle, I compared 

 with each other tl\e foa/x of the diiferent veflels. throuah 

 which it pafies» 



30* When the large branches of the branchial arteries 

 and veins, or the branches of the aorta, formed by the Jat- 

 ter, were plaped contiguous, they were found to agree very 

 neariy in thicknefs, elaflicety, snd texture; nor could I per- 

 cive that the fmalJ branclies of the branchial veins differed 

 from the fin^Ji braiiches of the artenea, or tliat any particu 



