Lymnæa stagnalis as an Intermediate Host of Fasciola hepatica

Abstract

THE possibility of British species of Lymnæa, other than L. truncatula, acting as vectors of Fasciola hepatica has remained a moot point since Thomas¹, in 1883, observed the miracidia to penetrate young specimens of L. pereger. The observation of Nöller and Sprehn², in 1924, added to the uncertainty, when by dissection of a young specimen of L. stagnalis they actually secured cercarise that were sufficiently far developed to show the lateral glands. As a result of experiments recently carried out at Weybridge, it can now be stated with certainty that F. hepatica is capable of completing its development in L. stagnalis with the ultimate emergence of cercariæ, which encyst and are capable of producing fluke infestation in mammals.