of the Salmon in fresh Water. 75 



Report of 1895, that fish continue to feed in the sea at least till the end 

 of August. The marked diminution in the amount of muscle in fish 

 reaching the estuaries in October and November would seem to show 

 that the supply of food is insufficient to yield the material necessary 

 for the rapidly growing genital glands, and that therefore the solids of 

 the muscle have to be drawn upon, or, at least, that accumulation of material 

 in the muscles is prevented. The steady increase in weight per fish of 

 standard length throughout the season seems to indicate that they con- 

 tinue to feed even after August and (September, though, as will be 

 shown later (p. 86), the flesh contains about 5 per cent, more water 

 in October and November than in July and August, while the increase 

 of weight is only 3*7 per cent. 



2nd. The fall in the amount of muscle from the early to the late put 

 of the season in fish in the upper reaches supports the conclusions 

 arrived at by Meischer Ruesch, and by Drs. Gulland and Gillespie, 

 that the salmon does not feed in fresh water. 



3rd. Light is thrown on the question of whether fish entering the 

 river early in the year go straight up and occupy the upper reaches, 

 leaving the lower parts to be occupied by the later-coming fish. 



The following facts bear specially upon this : 



(1) The length of the fish coming to the mouth of the rivers is practi- 

 cally the same from May to August (pp. 68 and 69). But in October and 

 November a markedly larger class of fish appears in the estuaries. In 

 the upper reaches, however, the size of the fish remains constant till 

 October. This would seem to show that from early spring to August 

 the fish pi-ess upwards, but that after this the later arrivals occupy the 

 lower reaches of the river. 



(2) The fact that the weight per fish of standard length steadily rises 

 in the estuaries throughout the season, and rises in the upper waters also 

 until July and August, seems to show the passage of fish to the upper 

 reaches during these months. But there is no increase of the weight of 

 the upper-water fish in October and November corresponding to the 

 increase in weight of those at the estuaries. This supports the view that 

 the early-coming fish pass on to the upper reaches. 



(o) The weight of the musculature increases in fish coming to the 

 mouth of the rivers from May to Atigust. There is also a slighter 

 increase in fish in the upper reaches, due probably to the immigration 

 of these more muscular fish from the mouth. But in October and 

 November, while the estuary fish show only a slightly less developed 

 musculature, the fish in the upper reaches show a very marked diminu- 

 tion, indicating that immigration from below has practically stopped. 



These conclusions are further supported by the evidence adduced in a 

 footnote of the Appendices of the Twelfth Annual Report to the Fishery 

 Board, 1893, pp. 55 and 56 : 



" If fish ascended the rivers in the spring of the year only to rid them- 

 selves of sea-lice, sis some consider, they might be expected to ascend 

 only a short distance ; whereas, it seems, on the contrary, that in some 

 rivers, at any rate, they press up immediately to the head waters. 

 Thus, in the Forth District, it is said to be the floods in January and 

 February that induce the fish to ascend to Lochs Venriacher and Achray. 

 In the 'Tay District, the fishing is best in the Loch Tay in the early 

 months of the year ; and I am informed by a gentleman well acquainted 

 with the fishings at the foot of the falls of Tummel, that it is the M:irch 

 floods that give a successful season in those waters, whereas the autumn 

 fish do not ascend so far. The superintendent of the river Dee, in 



