EXPLANATION OF PLATE XXIV. 



1. A fully-developed Redia, showing 



a. A young Redia. 



b. The Mouth. 



c. The Stomach. 



2. Represents the Life History of the River Fluke. 



1. The Fertilized Egg. 



2. The Ciliated Embryo. 



3. The Sporocyst 



4 The Redia. 



5 The Cercaria. 



6. The Encysted Cercaria (Pupa). 



7, The full-grown Fluke. 



3. A Portion of Stem of Grass, showing 



a. The Cysts fixed to the same, each Cyst containing the Pupa of 

 the future Liver Fluke ready to be swallowed by Sheep. 



4. A Cercaria of Liver Fluke, showing 



a. The Tail, by which it swims. 



b. The Cyst or Envelope. 



5. A full-grown Fluke, showing the Digestive System, and 



a. The Mouth. 



6.' An Adult Fluke, showing the Reproductive Organ as Branches, and 

 a. The Mouth. 



