4392 Dublin Natural History Society. 



in the spawning operations. This curvature of the under jaw is peculiar both to the 

 male salmon and the trout, and which is more or less developed according to age or 

 state of health of the fish. On the ascent from the sea the hook is merely observable, 

 but after the exhaustion of spawning the reduced condition of the fish renders it more 

 conspicuous ; and should obstacles prevent the proper period of return to the sea, a 

 cartilaginous extension takes place (whence it is called Carraughabaugh), but which 

 disappears on the renewed health of the fish, in its visit to the sea. In aged fish, par- 

 ticularly in large trout, this curvature becomes permanent in its enlargement, forming 

 a deep fossette in the upper jaw. Without a good foundation of scientific and prac- 

 tical knowledge combined in the pursuits of such subjects, it is a task of great diffi- 

 culty to select with judgment the plausible opinions that are frequently advanced by 

 writers of known character, but who at the time perhaps only possess general views of 

 the matter of which they treat. Thus, Mr. Keiller, in ' Lloyd's Scandinavian Ad- 

 ventures,' states the habits of the salmon of the Save, in Norway, to be such as are 

 altogether different from that of the British Isles ; forming no channel for the deposit 

 of the ova, but allowing them to float down the stream, impregnated by the milt, 

 similarly floating, and, finally, whatever escapes the rapacity of the river fish settles in 

 some crevice or rock until the fry is excluded. This is so contrary to the natural 

 principles of the family of the true salmons as scarcely to be worthy of dependence; 

 for, more probably, the floating ova that escaped the maws of hungry trout would 

 settle in some quiet pool beyond the medium of maturation, and finally perish. In 

 fact, it is characteristic of the Clupeidae or herring family, which, in the spawning-sea- 

 sons, seek the inlets and shallows of our shores, where the excluded ova, in myriads, 

 float away at the mercy of the tides ; besides, a far greater distinction exists in the 

 specific gravity of the ova of the salmon, the trout, and the herring — those of the former, 

 the greater portion sink at once to the bed or furrow, where they are impregnated by 

 the male, and remain without removal. In the Clupeidae, expulsion of the ova in 

 masses spread far, and float a considerable time, even where no force of tide or wave 

 would drive. We know of that family that the shad — both Alosa finta and Alosa 

 communis — ascend in the early part of summer from the sea to the fresh water to 

 spawn ; but they seek the sluggish parts of a river, or the quiet waters of the lake, 

 where the ova float, to be impregnated, similar in habit to the herring. The shad has 

 been taken in salmon-nets in the lakes at Killarney, and in rivers in Kerry. Some 

 discussion also arose in the Society that the clean spring fish ascending the Caragh 

 river, in the county Kerry, in January, remained in the fresh water throughout the 

 summer, and spawned the following autumn without revisiting the sea before spawning. 

 It is necessary, for the proper development of the ova and milt, that the fish should be 

 in the healthiest state of vigour ; consequently a sojourn in the fresh water for so many 

 months must greatly deteriorate the condition of the fish, and render them unequal to 

 such important functions. The wild and romantic districts in Kerry, which supply 

 the waters of the Laune and the Caragh, have for years been familiar to me. Its sal- 

 mon- fisheries, therefore, would naturally inter. st me. Salmon are found ascending 

 the Caragh very early in the autumn for the spawning-beds, being at that time, in 

 August and early in September, with the ova largely developed. These are the early 

 breeding fish, and subsequently are the run of early spring salmon. After the opera- 

 tions are completed in the spawning-beds, the fish return to the sea to recruit, and are 

 again to be met early in January, in the fresh water, in the primest condition. These 

 fish do not then visit the river or lake for the purpose of spawning, nor remain until 



