32 



THE CHIEF FORMS OF ENTOZOA WHICH 

 AFFECT MAN. 



BY 



W. B. BILLINGHURST, B.A. 



Abstract of a Paper read at the Meeting of the 

 Society, on 27th May, 1903. 



The paper dealt principally with the three chief families of 

 the Entozoa, viz. : — The Cestoda, the Trematoda, and the 

 Nematoda. 



As examples of the first group, Taenia Mediocanellata, Taenia 

 Solium, Bothriocephalus Latus, and Taenia Echinococcus were taken. 

 Specimens of these various forms were shown, and the anatomy 

 and methods of reproduction explained with the help of 

 diagrams. The life-history, with its marked alternation of 

 generations, was traced from the egg of a ripe proglottis to the 

 six-hooked embryo, and then to the Cysticercus or bladder 

 worm developing in the first host, and giving rise to the adult 

 form when introduced into the second host. 



In the case of the first three forms, man is the final host in 

 which the adult worm develops, but Taenia Echinococcus only 

 invades the human subject in the intermediate or Cysticercus 

 form. 



The life-history was illustrated by specimens of Cysticerci 

 in pork and beef, and also of a hydatid cyst (T. Echinococcus) in 

 a human lung. 



The Distoma Hepaticum, Bilharzia Hcematobia, were taken 

 as examples of the Trematoda. 



After a brief description of the anatomy of the Distoma 

 Hepaticum, or Liver Fluke, its extremely interesting life-history 

 was dealt with in some detail. Leaving the body of the sheep 

 as an egg, the embryo soon develops, and this having bored its 

 way into its host, the Limnceus Truncidatus, gives rise to the 



