Fig. 1. Diagram of the life-history of the Liver-fluke. The egg 



hatches out into a free-swimming embryo (ai) ; this if it finds its 

 snail changes into a sporocyst (a 2 ) ; this produces inside itself a 

 number of rediae (b) ; which in their turn each produces a number 

 of cercariae (GI). These, if conditions are favourable, find their 

 way into a sheep, where they grow up into the adult Fluke (c^). 

 (a\ cj, magnified; c% natural size.) 



