110 



PARASITES OF MAN 



the still more recently expressed opinions of MM. Bertolus and 

 Dtichamp, based on experimental researches, render it tolerably 

 certain that Leuckart' s original surmise was correct, and that 

 we must look to freshwater fishes for 

 the larvse of the broad tapeworm. In 

 the section of this work devoted to the 

 parasites of fishes I shall make par- 

 ticular allusion to the experiences of 

 Dr Bertolus; but as confirming the view 

 of Leuckart I may here observe, that 

 Bertolus has almost proved that the 

 so-called Ligula nodosa infesting the 

 common trout is merely a sexually in- 

 complete example of Bothriocephalus 

 latus. The bleak (Leuciscus albumus) 

 shares with other freshwater fishes the 

 privilege of harbouring a species of 

 Ligula (L. digrammd) ; but whether 

 this form bears any genetic relation to 

 our human Bothriocephalus latus can 

 only be determined by actual experi- 

 ment. If, as Duchamp and others have 

 either indicated or implied, Ligula al- 

 burni is a synonym of the bleak's ces- 

 tode in question, then it is evident that 

 the sexually mature form of the Ligula 

 of the bleak is the well-known L. sim- 

 plicissima of many water birds and of a 

 few other aviaa species. Probably the 

 bleak-eaters of Holland consume many 

 kinds of freshwater fishes, including 

 various species of the salmon and trout 

 family. 



The symptoms occasioned by Bothrio- 

 cephalus latus do not differ materially 

 from those produced by other tapeworms. 

 According to Odier, as quoted by Davaine, there is not unfre- 

 quently a tumid condition of the abdomen, with sickness, 

 giddiness, and various hysterical phenomena occurring at night. 

 Pain in the region of the heart, palpitations, and faintness are 

 also mentioned. 



As already hinted, this cestode is very liable to present 



Fio 2? 



Strobile of Bothrioctphalus 

 cordatus. After Leuckart. 



