88 
them. Salmon deteriorate in condition the moment they leave 
the salt water, and it is difficult to believe it, but nevertheless 
it is a fact, that these fish undergo a long fast of ten or even 
twelve months before they are sufficiently matured to spawn. 
This means that, in the course of time, the body shrinks and be¬ 
comes very much emaciated and discoloured, so much so that it is 
not easy to recognise the bright silvery-looking fish which entered 
the river some months before. In consequence of this great 
change in the fish owing to the prolonged fast the outer coating ot 
the scales becomes too large for the body, and the edge ot the 
scale gets disintegrated and ragged—much of it disappears alto¬ 
gether. 
One reason why this takes place is that, in consequence of the 
low condition of the fish, it is unable to nourish the outer edge of 
the scale. Just as the leaf of a tree begins to wither at its outer 
edge when autumn comes on, and the sap of the tree descends, so 
the outer edge of the scale of a fish is affected when the body is 
unable to provide nourishment for it. 
This, then, is the first step towards the spawning period of a 
fish’s life, and you will observe from the slides how interesting 
this is in the study of fish-scales. 
After the salmon spawns, it returns in course of time to the 
sea, where it quickly recovers its condition, but it still has this 
injured portion of the scale. The wound, with voracious feeding, 
soon heals up, and the scale recovers its normal condition, but the 
healed-up wound is still to be seen on the scale—a veritable 
cicatrix or scar—and this is the clue to be found which 
determines the important fact as to whether a salmon has spawned 
or not. Before scale examination gave us some information re¬ 
garding the life of a salmon it was commonly supposed that salmon 
spawned every year, but research has upset that idea, the real fact 
being that few salmon spawn more than once, a very few twice, 
and it is a most rare thing to find a scale showing three spawn¬ 
ing marks, though I have in my possession a slide which shows 
three spawning marks, and a disintreg rated edge to 
the scale which proves that this fish had spawned four 
times, as it was caught as a kelt returning to the sea after its 
fourth spawning. This fish was caught in the experimental nets 
at the mouth of the River Add, Argyllshire. It was marked, and 
if it returns again to this river, which it may do next summer, it 
should bear on its scales no less than four spawning marks; and, 
so far as my experience goes, such a scale has never been found 
up to this date.. It would be a most valuable addition to any 
student's collection of fish-scales. 
Such, then, in a condensed form, is the history of a salmon 
as told us by a study of its scale. 
Sea-Fish. 
The same characteristics of periodic growth are marked on the 
scales of many of the sea fish. 
