AND CIRCULATION IN FISHES. 1S9 



/tippliesthe numeroiis and large inufcles and fins on the Hde- 

 of ihQ fish> as £)r down as the Hns near to the anus» 



19, At laft to the frtmk T before inentioned, is added 

 a large vein X, on e.^ch flde, which conveys the blood froni 

 the under vein S of the fourth gill, and both veins V. W. of 

 the fifth gill (/); and^x^e are led by it to a great velTel Y,wliich 

 now airrinies plainiy the office of an artery refenibHng our 

 aorta defcendefif* 



ao, Froni the fore-part ofthis trunk two large branches 

 i^ d» analogous to our caeliac ^n^ mefmteric arteries^ are fent 

 offto the cliylopoietic vifcera; a fmall branch from which en- 

 ters the liver, . refembling our hepatic artery (tii), 



21. From the lides of the aorta the organs of generatlon 

 and urine are fupplied by fmall arteries e^ e. e. e, etc* and from 

 thc lower part of the trunk are fent oftwolateral branchesj^ 

 f , that may be compared to our iHac arterier, and which fup- 

 ply the mufcles and fins at the lower part of the body. 



22. A middle arteri/ g runs firaight down into the tail 

 covered and prote<fled by cartiiage aiid terminates the aortic 

 fyflem. 



23» From the remarkable courfe of the arteries of the 

 heart and of the branchial and hepatic arteries, fimilar to that 

 in man, we fee clear proof, that the blood^ which, after pas» 

 ling through the gills, has undergone one circulation, orra- 

 ther here has pafled through one artety and one vein ^, is unfit 

 fbr fome office or offices, which are performed by the blood 

 in the heart, gills and liver» 



24* Nutrition only has been mentioned by authors; but 

 ito fullv fatisfving reafon has as yet been given, whv bv one 

 circuiation the blood fliould ^become unfit for this purpofe 5 



Aa 3 and 



(/) Tab. i.fig. 5. 



(f») Tab. lil. R. S. T. U. V, W» 



