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 



mail is of spotless purity ; but a sojourn of two 



Seasonal . ^ J . ' . J n ... 



change in or three weeks in the river, especially it the air 

 ice * 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 ? 



13 



