136 MALIGNANT FUNGUS 



Paint protects the bottoms of iron ships from barnacles, 

 etc. The fungus is in itself harmless, but it sometimes 

 contains worm-like parasites of microscopic character. 

 These harbour themselves in that portion of the 

 fungus near the skin of the trout, and are continually 

 eating into the tissue of the fish. The mouths of 

 these worms are armed with tentacles, with which 

 they can adhere to any portion of the trout's skin 

 which may be unprotected by slime. 



If the worms be killed by salt solution, the fungus 

 then disappears. If, however, any portion of the living 

 and malignant fungus be returned to the water, it will 

 carry with it a percentage of these deadly and con- 

 tagious worms, and hence the necessity of its absolute 

 destruction for the benefit of the healthy trout in the 

 same stream. Mr. Thomas Clinker, the manager of 

 the Itchen Trout-Breeding Establishment, considers 

 that there are two kinds of fungus the one malignant 

 and epidemic, and recurrent in places where the sur- 

 roundings are unhealthy and the water-supply feeble ; 

 the other universal, but comparatively harmless. I 

 quite agree with this view, the real harm being due to 

 the parasitical worms, which may or may not exist 

 in the ordinary fungus. The bare places caused by 

 the fry nibbling one another are an ever-present source 

 of danger to these small fish. 



