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parasite ? Can it have anything to do with the disease ? 

 The cause of death did not appear clear, looking only at 

 the head, gills, throat, and heart, as, with the exception of 

 the bit of gill sent, these organs seemed right." 



On May 1st, and again on the $rd, I submitted Mr. 

 Simpson's specimens to microscopic investigation ; and 

 although neither the long " white body " in the muscles, 

 nor a similar filamentous band two inches in length, and 

 loose in the bottle, turned out to be tapeworms, it was 

 soon perfectly clear that the mass of parasites from the 

 "flesh" were cestode worms. Some were in capsules, 

 whilst others had been liberated, but all, whether encysted 

 or free, were sexually immature. 



The examination, in fine, led me to conclude that the 

 parasites were very young examples of Ligtda digramma, 

 and as such, immature specimens of the Ligula mono- 

 gramma of water-birds. It would seem from M. Duchamp's 

 experiments that after transfer to the ultimate host 

 their arrival at maturity is excessively rapid, an interval of 

 four hours being sufficient for the formation and perfection 

 of the eggs of the parasite. Here, however, I am chiefly 

 concerned to remark upon the circumstance that although 

 Mr. Simpson's lake trout was suffering from Saprolegnia, 

 that external parasite was not alone the cause of death. I 

 believe that the larval ligules were in this case the chief cause 

 of the fatal issue. The number of ligules was something 

 extraordinary, and the fish must have succumbed if there 

 had been no Saprolegnia. Judging from the sections sent, 

 every part of the great lateral muscle-mass seems to have 

 been stuffed with the larvae, precisely as one finds measly 

 beef and measly pork overloaded with cysticerci. Clearly 

 it follows that if a diseased fish of this kind were devoured 

 by one or more water-birds, the avian host or hosts would 



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