LECTURE XX. 



Flukes or Trematode Parasites are comparatively rare in Man 

 The Billiarzia httmatobia forms a Notable Exception Formi- 

 dable nature of the Disease thus Produced The Ciliated Larvae of 

 this Entozoon display a Complicated System of Aquiferous 

 Vessels Case LXXXI. Comments on the Peculiarities of the 

 Disease, with an Exposition of the Principles which should guide 

 us in the Treatment of Cases. 



GENTLEMEN, The last form of helminthiasis which 

 I propose to bring under your notice, is that arising 

 from the presence of flukes in the human body. 

 It is a fortunate circumstance that the disorders 

 caused by trematode parasites are comparatively 

 rare ; at least they are so in European countries, 

 and especially in our own islands. In Africa, 

 however, the case is far otherwise, as I shall imme- 

 diately show you. Of the nine so-called species of 

 fluke recognised as human entozoa, four have only 

 been once observed ; another has been twice or 

 thrice noticed; yet another three times, and one 

 other on four occasions ; whilst the so-called sheep- 

 fluke (Fasciola hepaticd) has occurred about twenty 

 times in all. There is one fluke worm, indeed, 

 of terrible importance, inasmuch as its entrance into 



