( 95 ) 



I have attentively examined one of thefe oval particles on the ed^, 

 as is fcen at E, I have found it exhibit a flronger blcod-red than 

 where three particles lay flat one on another. 



Among the tadpoles, which I caufed to be taken out of the canals, 

 I perceived a fevv' very fmall ii flies, having their fkins marked with- 

 dark fpots, fome of wliich were of the figures of little fiars. This fpc 

 cies of fifli I judged to be of its full fize, becaufe I had never feen any 

 by the naked eye of the fame fliape as thefe appeared v^hen magnified. 

 One of them I placed before the microfcope, and, upon obferving the 

 finny part which conftitutes the extremity of the tail, I plainly faw 

 the fame kind of flender arteries and veins as I have before defcribed,. 

 thiough with more difficulty than in the tadpole, partly, becaufe 

 this fifli did not long continue quiet, and partly becaufe the parti- 

 cles of Blood (which, in thefe obfervations appeared to me no 

 other than globules) were much fmaller than in the tadpole. Thefe 

 arteries and veins v-.ere placed near the boney parts, or rifings, v*hicli 

 give ftrength to the fn at the tail, and in them I faw the compleat 

 circulation of the Blood ; for, on both fides of each of the before- 

 mentioned boney parts was an artery, which had a bending, or back- 

 ward turning at its extremity, and thus became the beginning of a 

 vein. 



Upon vievv'ing this fim's tail, at th.e part where the fin begins, I. 

 tliere faw, to my great admiration, a large artery dividing itfelf into 

 tlie before -mentioned fmaller ones ; and clofe to it, numbers of the 

 minute veins returning from the fin, and uniting in one large vein. 

 In fliort, here was fuch an agitation, or motion of the Blood driven 

 out of the large artery to the fartheft end of the tail and into the fin, 

 and running back in the fmall viens, into the large one, as is incon- 

 ceivable. 



In order to Ihew the fize of this little fifli, wherein I obferved all 

 thefe motions of the blood, I caufed a figure of it to be drawn, as it 

 appeared to the naked eye, and this is fliewn in Plate IV. fig. 4. At 



