Fasciola hepatica L., a Tissue Feeder

Abstract

ABOUT two years ago I published in these columns a short account¹ of the burrowing and feeding activities of juvenile forms of Fasciola hepatica in the livers of mice. This note was based on a more detailed study which proved that these young flukes eat their way through the liver, feeding chiefly on hepatic cells². The oral sucker is used to pinch and burst hepatic cells one by one, and a homogenate of liquid cytoplasm and broken tissue is aspirated by the pharynx and ingested. By the time the fluke has just entered the liver some hundreds of hepatic cells have been excavated in this way, and as the fluke grows an enlarging oral sucker broadens the burrow so that the toll of hepatic cells becomes enormous, even in moderate infections. Burrowing involves damage to sinusoids and consequent hæmorrhage and some blood is ingested; but the young fluke is a tissue-feeding animal in the true sense of the term and not a blood feeder as is commonly supposed.