THE SALMON. 181 



usual quantity of oil found in a so-called seasonable salmon. Neither 

 of the fish had ever spawned, the ovaries being in a semi-embryonic con- 

 dition, and weighing only 7dr. in each, the oviducts also being in the 

 thread form, never having been fully developed, as in the fish that have 

 spawned, and from the quantity of fat on the gut and pyloric appendages, 

 I consider they had been only a short time in the river. I may also 

 mention that all the fish, both trout and salmon, had tapeworms of large 

 size, 2yds. in length, and 3-1 6th of an inch in breadth. One salmon 

 had from 60yds. to 80yds. of these worms in the pyloric portion of the 

 gut. I have preserved the young in situ. . . . From the effect upon 

 my hands in the course of manipulation and working with the affected 

 carcases, I have reason to think that the plant is a very pungent, if not 

 poisonous, one." 



I may here mention that four painted casts of the stages of this disease 

 may be seen at the Museum of Fish Culture, South Kensington. 



According to Mr. W. J. Smith, who published some excellent drawings, 

 and a good description of its various changes and developments in the 

 Gardeners' Chronicle for 4th May, 1878, it afflicts not only salmon and 

 trout, but eels, lampreys, flounders, minnows, &c. I have identified it 

 myself on carp and eels, and I am strongly persuaded that the "gill 

 fever ' ' of young fish is due to a growth of the same family. 



The question which naturally arises is, "What is the cause? " This 

 has been variously answered ; but as yet no definite conclusion has been 

 arrived at. It has been suggested that sewage, guano, the want of 

 freshets when the fish are on their way to the sea, overcrowding, factory 

 refuse, mine water, &c., are each and all responsible for the effects 

 described. 



Professor Stirling observes = " I am quite unable to say what the cause 

 of the fungus may be, but as I found foreign matter of various kinds 

 entangled in the mycelium of the fungi, I have pretty good grounds for 

 thinking it may have arisen from pollution. The foreign matter found in 

 the mycelium or fronds of the plant were torulae, or yeast fungus, triple 

 phosphates, fecula, human hair, and hairs of cat and mouse, also dismids 

 and diatoms, shreds of dyed wool and cotton, with other fragments of 

 matter unknown to me." 



I have repeatedly noticed that the presence of fungi on other fish is 

 invariably coeval with these larval cestodes. In order to give some idea 

 of the tremendous decimation of these noble fish during the season of 

 1877-8, I may mention that, according to the official report, as many as 

 1451 fish (all salmonidse), were buried from the river Eden between 1st 

 March to 20th May, 1878. 



The kelt is almost invariably infested with a white worm and a 



