BY W. SAVILLE-KENT, F.L.S. 57 



propagate and grow to maturity in its lakes and rivers without 

 requiring to migrate to salt water, and which race might be 

 most appropriately distinguished by the title par excellence of 

 the " Jubilee salmon." I fear, however, that the prospects of 

 this achievement are not altogether encouraging. 



On September 1st I visited the establishment at the Eiver 

 Plenty, with the object of making myself perfectly acquainted 

 with all the details and circumstances attending the breeding 

 and development of these fish which are now laid before you. 

 From the approximate number of 4,000 fertilised ova obtained 

 by artificially stripping ten female and as many or more 

 male fish, 2,000, or 50 per cent, of dead ova had been already 

 abstracted. It is plain from their appearance that a very large 

 portion will have yet to be removed, and that, as commonly 

 occurs under similar conditions, there will be a large number 

 of deformed fish among the fry that may hatch out. All the 

 ova, in fact, are exceedingly small and wanting in that density 

 and tenacity of the investing membrane as compared with those 

 of mature sea going salmon. The circumstances that have to be 

 recorded concerning the parent fish are, I regret to say, scarcely 

 more promising. Out of the stock of 30 no less than 17 have 

 died. What is more unfortunate is the fact that 14 out of the 17 

 were male fish, so that it is doubtful whether any male fish 

 are left for future experiments. The ultimate cause of the 

 death of these fish has been the attacks of the fungus disease 

 described in the earlier paragraphs of this paper, and the 

 thread of which subject may be again taken up with reference 

 to its special manifestations in association with and bearings 

 upon these particular fish. The fungus, as I have determined 

 to my entire satisfaction, is indistinguishable from the 

 cosmopolitan species, Saprolegnia ferax, already described, and 

 which engenders a similar disease among Salmonidse in the 

 three continents of Europe, Asia, and North America. 



The form under which this disease has manifested itself at 

 the Salmon Ponds is not that of an epidemic attacking clean 

 and healthy fish, but has in all cases been associated with fish 

 that have received injuries attendant upon the operation of 

 spawning, or at a time when their system is in a low and 

 exhausted state, and, as it were, predisposed to the attacks of 

 the parasitic fungus. The artificial conditions under which 

 the salmon are necessarily maintained at the Ponds is 

 undoubtedly accountable to a large extent to the high rate of 

 mortality among them that is here recorded. Left to follow 

 their natural instincts these fish immediately after spawning 

 would have dropped down stream to the saltwater, and which, 

 as has been ascertained by direct experiment, has the effect of 

 entirely eradicating the fungus from their system. As a matter 

 of fact, I may state that these small parr-marked spawning 



