ZOOLOGY OF THE INVERTEBRATA. 



801 



B. — Anterior portion, more highly magnified. 



1. Cirrus sac. 



2. Ductus ejaculatorius. 

 Female aperture. 

 Ovary. 

 Oviduct. 

 Penis. 

 Shell gland. 



8. Anterior testes. 



9. Uterus. 



10. Vasa deferentia. 



11. Vesicula seminalis. 



12. Yolk gland. 



13. Its duct (from Marshall and Hurst, 

 after Sommer). 



C. — Genital sinus and neighbouring parts. 



1. Ventral sucker. 



2. Cirrus sac. 



3. Genital pore. 



4. Evaginated cirrus sac (? penis). 



5. End of vagina. 



6. Vasa deferentia. 



7. Vesicula seminalis. 



8. Ductus ejaculatorius. 



9. Accessory gland (from Sommer). 



D. — A ciliated internal end from the excretory apparatus. 

 I. — Orifice of the flame cell (highly magnified). 



E. — Egg of Fasciola hepatica^ x 330 (from Thomas). 



Explaiiatmi of Fig. 78 (page 302). 



14. Lips of redia. 

 15; Collar. 



16. Processes serving as rudimentary 

 feet. 



1 7. Embryos. 



18. Trabeculae crossing body cavity of 

 redia. 



19. Birth opening. 



20. Morulse. 



21. Oral sucker. 



22. Ventral sucker. 



23. Pharynx. 



All from Marshall and Hurst, after 

 Thomas. 



Accompanying these two illustrations we have a good descrip- 

 tion of Liver fluke, with a most interesting account of its life- 

 history, of which we regret our space will not allow us to make an 

 extract. It has been computed that each fluke produces half-a- 

 million eggs. 



