56 NATURAL HISTORY SOCIETY OP DUBLIN. 



As I observed, it is not my intention to introduce at present the 

 variety of forms that the Salmon and the different species of Trout as- 

 sume according to the locality or to the condition of the lake or the river 

 frequented; for it will hereafter be of interest to di]ate upon all those 

 changes that occur among them, as also among those of the sea fish around 

 our coasts. Even those that are presumed to be migratory, as the herring, 

 strongly evidence such facts. It is well known that these peculiarities 

 affect herrings, even in lochs adjacent to each other, as in Scotland in 

 those of Loch Duich and Loch Long. The superior excellence of the 

 herring of Loch Fyne is well established, and our own Dublin Bay 

 herring cannot be surpassed in flavour and richness. 



Much of interest has recently been written on the introduction and 

 acclimatization of Continental fish to the British Isles, and of transport- 

 ing the ova of our Salmonidae to the remotest of our colonies. It has 

 been largely dwelt on the valuable experiments recently carried on, in 

 showing the prolonged vitality of the ova imbedded in, or placed upon 

 ice, and on the effect in retarding the period of the extrication of the 



fty. 



At a meeting of the Society in February, 1845, I gave an outline of 

 many of the lakes and rivers of this country that were barren of useful 

 fish, and how productive they might be formed by the introduction of 

 such fish as the Aspro vulgaris, the Zingle of the Rhone and the Danube, 

 the common pike perch, the Lucioperca sandra of the Danube, the Elbe, 

 and the Oder. These fish attain a great size, as also the Salmo hucho 

 of the rivers tributary to the Danube. All those fish, however, are ex- 

 ceedingly predatory and voracious, requiring large supplies of food, and 

 therefore would be a dangerous introduction into some of our Salmon 

 rivers, whose streams are characterized by the absence of the pike and 

 the perch — man being their chief enemy at seasons when full protection 

 should be given to the breeding and the young fish. In those fine sheets 

 of water in Cumberland, Keswick Lake, or Derwent "Water, and Bas- 

 senthwaite "Water, the numerous large pike and perch are injurious to 

 the increase of the Salmon and of the Trout. It has been well established 

 that for a period of 150 days the ova of the Salmon might be retarded in 

 its development by the severity of a winter season. Some years since, I 

 passed a winter at Kirkby Stephen, in Westmoreland, a pretty village on 

 the banks of the Biver Eden. The winter was so prolonged and severe, 

 that heavily laden waggons passed over the ford on the ice. Above the 

 ford were spawning beds ; and so deep had the water become congealed, 

 that the stream was almost a stationary solid mass, having only in parts 

 a limited trickle. The following season the fry were abundant. These 

 facts were well known in years past, in the northern rivers of Scotland, 

 when the winters were unusually severe. 



A friend, who had often fished the rivers of Kerry, writes to me 

 from Auckland, New Zealand, where he is now stationed — " It would 

 make you indeed sad to see such fine rivers, for instance, the "Waikato, 

 without a Salmo solar or a Salmo ferox ; one would think at every turn 

 that you would rise them ; but no ! all are empty." New Zealand is a 



