144 FISH HATCHING. 



circulation under a high power I was assured 

 of there being matter other than blood cor- 

 puscles circulating in the veins, and, on further 

 examination, came to the conclusion that 

 there were globules of fat mixed with the 

 blood. On examining into the course of the 

 circulation I find that the blood is conve^'ed 

 from the heart (which is visible just under 

 the gills of the fish) into the liver by a branch 

 of the large trunk artery, which, after giving 

 out branches to the intermediate spaces be- 

 tween the ribs, to the kidneys, &c., is finally 

 lost in the ring of muscular fibre in the tail ; 

 that from the liver, part proceeds by the 

 large vein, shown in drawing "No. 2, straight 

 to the heart ; the remainder, after ramifying 

 over the umbilical vesicle of the fish, is finally 

 collected in the large vein (inferior vena 



