INTRODUCTORY xvii 
Lord Elgin’s Commission in 1901 I heard the asser- 
tion made that salmon spawn in the sea as well as 
in fresh waters, and I have met more than one 
tacksman of salmon fishings who insisted that a 
grilse was a different species of fish from a salmon. 
These views die hard, especially when there seems 
to be some commercial advantage in holding them. 
Since the great development of rapid transit by 
which fish can be sent to market, the use of ice, 
and especially since the sharpening of competition 
amongst salmon fishers and the consequent great 
improvement in methods of fishing, a more exact 
knowledge of the life of the salmon has become more 
and more necessary. We not only require to know 
when the fish breeds, and that it can only reproduce 
its species in our rivers, but we want to know how 
often the fish breeds in its lifetime—or, perhaps one 
should say, how seldom it breeds; at what age it 
begins to breed and at what age it ceases to breed. 
We also want to know its habits of migration to and 
from fresh water, and how much time it spends in 
the sea; whether fish migrate from one river to 
another, and where salmon go in the sea, what the 
salmon’s food is and when it is in best condition. 
More than this, for the better regulation of the 
fisheries we want to know the conditions which 
govern fish in ascending rivers and tributaries—a 
subject of value to netsmen and anglers alike. 
These are definite points of practical importance 
nowadays, for on a thorough knowledge of the life 
history of the fish itself can sound regulative treat- 
ment alone rest. 
b 
