THE DISEASES OF FISH. 39 



good water and good food, or else they will lose 

 their vigor and activity, and soon become thin and 

 emaciated and die a lingering death. 



Of course, there are certain kinds of fish so con- 

 stituted that they can endure greater hardship than 

 others, and it was a wise provision of the Creator, to 

 provide fish which were adapted to the peculiarities 

 of the different bodies of water, just as He created 

 mankind, organized so as to be able to withstand the 

 climate, temperature and atmospheric changes to 

 which the different parts of the globe are subject. 



It is therefore necessary, in the cultivation offish, 

 to provide for them the elements their natures re- 

 quire, in order that they may be healthful. As fish 

 are difficult to cure, the great secret is to properly 

 care for them, so they may keep free from disease; 

 in other words, the cure consists in the prevention. 

 In their wild state, fish undoubtedly die from the 

 same relative causes as the human race. They are 

 infested by a variety of parasites, etc. Tape-worms 

 are not infrequently found in their intestines; on one 

 occasion I took out of a minnow, not more than three 

 inches long, five tape-worms, measuring, when 

 stretched full length, from two to two and a half 

 inches. They occupied at least two-thirds of the 

 abdominal cavity. I took this fish on a small hook, 

 and it did not seem to be inconvenienced by the 

 extra load it was carrying. I have also found worms 

 imbedded in the solid flesh along the back of the 

 fish. 



Another disease which I have observed in trout is 

 the growth of tubercles in the gills. When these had 

 attained a size so as to separate the gills and inter- 



