THE SALMON 193 
locked” salmon of Lake Maine in the United States and 
of Lake Wenern in Sweden must not be overlooked. These 
fish have been pronounced by competent ichthyologists to 
be specifically identical with the true Atlantic salmon.* 
They never descend to the sea, and necessarily find their 
sustenance in fresh water. Their requirements are met by 
the resources of great inland sheets of water, into which 
they resort for food, and whence they ascend the rivers to 
spawn. 
We must now return to the point where we left the 
grilse or salmon. When it first leaves the sea its silver 
Saber mail is of spotless purity 5 but a sojourn of two 
change in or three weeks in the river, especially if the air 
appearances and water temperature be high, suffices to dim the 
lustre of its scales. The cause of this change and its process 
are far from being thoroughly understood. Popularly it is 
believed to be brought about by exposure to sunlight and 
by the fresh water acting as an oxidising agent; but there 
is this consideration to be taken into account, that, as soon 
as the salmon has spawned, and becomes what is known 
as a “kelt,” the discoloration begins to pass away, and 
before the fish regains the salt water it has become quite 
as silvery as when it left it. Moreover, as we have seen, 
the parr in passing into the smolt stage, before ever it has 
tasted salt water, puts on a bright silvery coat. All this 
seems inconsistent with any supposed oxidisation by the 
river water. We are dealing, not with real silver, nor any 
mineral, but with an organic substance known as guanin 
* The epithet “land-locked” is most misleading and ought to be 
discontinued. It is easy enough to provide obstacles against the ascent 
of a river by salmon; not so to prevent their descent. In Labrador 
ouananiche are found above falls one hundred feet in height. In 
descending such a cascade, many fish might be killed; but how could a 
salmon, which will exhaust himself in efforts to ascend an impassable fall, 
estimate the danger of descending one, and decide that it were safer to 
remain above ? 
T3 
