64 SALMONID^ OF BRITAIN. 



ice or snow-water, while on the other hand, a high temperature of the river- 

 water equally deters them from enteinug it.* Mr. A. Young, Inspector of 

 Fisheries in Scotland, remarked that as a general rule such Scottish rivers as fall 

 into the German Ocean and Portland Firth are "early," while those emptying 

 themselves into the Atlantic are " late." And he suggested that as the German 

 Ocean is a cold sea, so the slight difference between the temperature of its waters 

 and those of the rivers induces salmon to ascend early, Whereas rivers on the 

 west coast mostly descend from snow-fed sources, and are therefore cold, much 

 colder than the Atlantic, consequently the salmon wait until the snow floods have 

 ceased. It is also evident that the same comprehensive rule extends to the 

 English and Welsh rivers, and those on the east coast falling into the German 

 Ocean are earlier than those on the west, or of the south Coast of Devonshire and 

 Coi-nwall, where the warmer Atlantic or the English Channel would have the 

 same influence as pointed out by Mr. Young in Scotland. 



But there are also differences in degrees in the temperature of the waters 

 of rivers to be considered, which may be influenced by the estent of their course, 

 and the nature of the country through which they pass, as well as by the amount 

 of rainfall. Thus rivers which have their rise in mountains, and after a short 

 and rapid course fall into the ocean, would be colder than such as are longer and 

 more sluggish, and as Sir W. Jardine's and others' observations pointed out, that 

 in the colcl months salmon naturally select the warmer streams as well as their 

 most sunny sides. Rainfall has been observed to afford an index to the 

 temperature of rivers, for its distribution is dependent on the level of the land, 

 the result being that such as pass through districts with the heaviest rainfall, 

 would. Professor Huxley observed, be late rivers, while those traversing 

 lowlands where the rainfall is less, would be early rivers. According to this 

 view the waters of the Severn should be warmer than those of the Wye, which 

 latter should be of a higher temperature than those of the Usk, and the salmon 

 would ascend these rivers in the foregoing order, which is the order in which 

 they are tabulated among early and late rivers. f But it must be observed that 

 this theory respecting rainfall does not stand the test of examination throughout 

 Scotland and Ireland. 



Can any conditions of salmon ascending " early " or " late," or breeding earlier 

 or later, or completing their ova depositing within a shorter period of time, be 

 attributed to constitutional peculiarities affecting the local race of fish ? Two 

 main branches of inquiry would seem to be here indicated. First, are all these 

 early fish ascending in order to breed the same year ? Secondhj, what are the 

 constitutional peculiarities of early salmon ? 



It would seem from the few investigations which have been made that it is by 

 no means improbable that some of the early-ascending clean fish may be seasonally 

 sterile, although it is generally held that in many ova and milt may be discovered 

 on a microscopic investigation to be a very little developed, and although these 

 last would probably be among such as push on to the upper waters, it seems still 

 to require proof why it is that they should desire to remain so many months^ in 

 the stream, away from the sea. This gives rise to the very important question 

 of how frequently do salmon breed ?% ^^ f'^e United States Mr. Atkins has been 



* February 28th, 1886, a severe snow-storm set in, and as a result clean salmon were 

 checked ascending rivers, consequently but few catches were made, as may be seen from the 

 following London market prices of this fish. Of course fioating ice and cold likewise impeded 

 the fisherman's work. February 2Cth, salmon Is 4d to Is 8d per lb. : 27th, l.s- Sd to 2s : 28th, 

 Is 9d to 2s M: March 1st, 2s : 2nd, Is 9d to 2s Sd : 3rd, 2s M to 2s 8d : 4th, 2s 2d to 2s 6(/. 



f In the United States Professor Brown-Goode observed that salmon spawn on a fallmg 

 temperature, yet they seem to enter rivers on a rising temperature. In America the Southern 

 streams seem to yield the earliest iish. They are not sensitive to sudden changes, and are 

 capable of enduring a range of at least 45°. 



% We may dismiss as untenable one consideration which has been advanced, that they may 

 do so twice yearly ; still we possess the evidence of Mr. Buist that he spawned a particular fish 

 on two successive seasons, and of 3Ir. Broicn, who treated another similarly on two alternate 

 years, but where it was during the intermediate period of course it is impossible to say. Lastly, 

 we have Mr. Frank Buckland, who stated before a Parliamentary committee in 1877, that 



