BY R. GREIG SMITH. 357 



nuclear stains: they are the same shape and the same size; and, 

 lastly, they both have the cleft at the broad end, which Calkins 

 says is the first stage in the formation of the sporozoites. 



Marsh* also writes about the same disease among brook trout, 

 and mentions that Loch Leven trout are susceptible, but that 

 rainbow trout, kept in ponds by the side of the Loch Leven trout, 

 have not contracted the disease, and appear to be immune. The 

 experience at Prospect shows that the immunity must have been 

 accidental. 



* The Fishing Gazette, xix 401, 417. 



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