THE SALMON 213 
Some people have assigned temperature as the regulating 
cause, alleging that salmon ascend those rivers which are 
warmer than others in the early cold months ; but here again 
facts are against theory, inasmuch as some of the very earliest 
salmon rivers in Scotland—the Naver, the Thurso, the Brora, 
etc.—derive their volume from melted snow, and shrink to the 
scale of brooks when the snow is gone. I have seen large 
numbers of salmon ascending the Helmsdale in February when 
the water temperature was only 34° Fahrenheit. On Friday, 
February 23rd, 1900, the Helmsdale had been thickly frozen 
over for many days ; the ice, as well as the whole strath and 
surrounding hills, being deeply covered with snow. Daily the 
deer came cowering down to the lodge, seeking, poor things, 
for some stray wisp of straw, so hardly were they pressed for 
food. The cold was intense. That night there came a change. 
Next day the water came down in flood, the ice began to break 
up, great bergs and fields of it went crashing down the torrent 
and away out to sea. ‘The same went on all Sunday, but on 
Monday morning the river was clear of ice, though still very 
high from melting snow. 1 went a-fishing, much doubting 
whether any salmon could have had the hardihood to face such 
a state of things. Before night I had killed eleven spring fish, 
fresh from the sea, as could be seen by the sea-lice, an ugly 
parasite which drops off the fish soon after it enters fresh water. 
After that experience, I feel convinced that, although cold 
water may attract salmon, it is very far from deterring them 
from running. 
