Penetration of Fasciola gigantica Cobbold, 1856 into Snail Hosts

Abstract

I HAVE recently demonstrated¹ that penetration of Fasciola hepatica into Limnaea truncatula is a brief but elaborate process which involves the successful attachment of the miracidium to the snail, seemingly by suctorial adhesion, and the production of a secretion which cytolyses the integument of the snail in a circumscribed area underlying the anterior non-ciliated pit of the larva. Not until the snail's epithelium has been perforated by cytolytic action does the larval trematode thrust itself into the snail's body. By the time these preparations for entry have been completed, the miracidium has cast off its ciliated epithelium, so that although it is the miracidium which attacks the snail, it is the young sporocyst which enters the snail's body.