Median. — Goitre Amour/ Trout 65 



with unnatural foods, overcrowding, and an insufficient 

 water supply. 



One year the hatching- troughs were much overcrowded, 

 the next there was an insufficient supply of water. The out- 

 side ponds were all clean and there was undisputedly a suffi- 

 cient volume of water. The fish had, however, been overfed 

 during the necessary absence of the superintendent, with the 

 exception of a few short visits, from June until the first 

 week in November. 



That overfeeding was the principal cause was indicated 

 by a curious but convincing condition. Beginning with 

 number one pond, by the time number four was reached the 

 supply of cut lungs and liver began to run short, and the fish 

 in that pond therefore received not quite as much as those 

 above. The same thing happened to the fish in number nine 

 pond and number thirteen, and so on to the end. While 

 there was some goitre in number four and the others in 

 w hich the trout had been put on short rations, it was of small 

 extent and there was less fungus and death. 



Dr. Marine's investigations and the experiments of the 

 superintendent at the Spruce Creek hatchery pointed out the 

 remedy, and it was applied. A greater volume of water was 

 run through the hatching troughs, the trout in the ponds 

 were given several heavy salt baths, and the amount of food 

 considerably lessened. Although the ponds were not be- 

 lieved to be overcrowded, the number of fish in each was 

 lessened, and while cleanliness of ponds was the usual order 

 of things, attention in this respect was redoubled. 



It was not long before the trout J^egan to show a de- 

 cided improvement. Within a few months inflammation of 

 the throat sank" from ninety to less than fifty per cent, and 

 by autumn it was hard to find a case of incipient goitre in 

 the ponds. Old fish having the fully developed swellings of 

 course still retained them, but to all appearances they were 

 perfectly well. 



