PLA TYHELMINTHES 



205 



tissues of the snail, thrusting out its spike and rotating by 

 means of its cilia so as to bore in. Within the snail the 



Fig. 124. — The reproductive organs of a liver fluke, from the 

 ventral side.— After Sommer. 



c.s. Cirrus sac. 



f. Female aperture. 



g. Anterior lobes of gut. 

 m. Mouth. 



ov. Ovary (dark). 

 p. Penis. 



s.v. Seminal vesicle. 

 slug: Shell gland. 

 7 1 . Testes (anterior). 

 ut. Uterus. 

 v.d. Vas deferens. 

 y.gl. Diffuse yolk glands. 



cilia are lost and the larva increases in size and grows into 

 a hollow sac or sporocyst Sometimes this multiplies by 



