SEA-FISHERIES LABORATORY. 325 



began on June 22ncl, when two of our fish were found 

 dead in the pond, one at the surface and the other on 

 the bottom. The former was somewhat decomposed, 

 and appeared to have been dead some time. The liver 

 of both was densely crowded throughout with the rounded 

 whitish cysts, of which I sent you specimens, and there 

 were a few scattered about in the intestinal mesentery. 

 The condition of the water in the pond had given me 

 some anxiety for some time before the above-mentioned 

 date, and, as it became worse, it was decided to drain 

 the pond. This was done on July 3rd and 4th, and 

 resulted in the discovery of a considerable number of 

 dead and dying fish. Many of the former were so much 

 decomposed, that examination of the viscera was impos- 

 sible, but a few were in better condition, and the liver 

 of every one was more or less infected with the parasite. 

 The same remark applies to the dying ones. In most 

 cases the infection was complete, but there were several 

 in which only part of the liver was visibly infected. 

 Many of these fish had open sores or abrasions on the 

 top of the head, like those of the specimens I sent you 

 on October 10th, and all were much infested with a species 

 of Lepeophtheirus.* 



" What I have called dying fish were certainly 

 sickly. They swam about languidly, but I saw no 

 evidence of giddiness, or lack of co-ordination in their 

 movements. Some of them struggled gamely when 

 handled, but their general behaviour was not like that of 

 healthy fish. All the apparently healthy fish were 

 transferred to the lower storage tank on July 5th, and 

 were kept there, with as frequent change of water as 

 possible until August 7 th. In spite of this, the water 

 in the storage tank rapidly assumed the dirty brownish 

 *- ; '- Lepeophtheirus pectoralis (Miiller) 



