xiv INTRODUCTORY 
times over Church distinctions. Precisely similar 
lines of investigation have led contending observers 
to completely opposite deductions, the reason being 
that the observers were in reality striving for 
supremacy rather than for truth. 
No wonder, then, that critics find safety in saying 
we know very little about the salmon. They are, 
even at the present day, perhaps not far wrong. 
But writers seem to have acquired the habit of safe- 
guarding themselves by emphasising the “mystery ” 
or “dire perplexity” in which the whole subject is 
shrouded. One of the most recent tells us that the 
result of the whole body of literature on the salmon 
is to give the Philistine “ numerous erroneous ideas 
on the subject, along with a few ‘proved facts.’” 
It is clear that he does not think much of the 
“proved facts ”—regards them apparently as on the 
same level with the judge’s famous characterisation 
of the evidence of the skilled witness. 
With humility, however, we must plod on search- 
ing for our facts if we hope to gain that true con- 
ception of our subject which can alone give us a 
scientific basis from which to extend a sound regu- 
lative treatment of our salmon fisheries. Alexander 
Russel has truly said, concerning the importance of 
this matter, that “ without some knowledge of how, 
when, and where the fish breeds, dwells, and feeds, 
it is useless to speak and unsafe to act.” 
The general principle lying at the root of all 
salmon fishery legislation has been to counteract 
the natural tendency of man to over-fish, to capture 
fish at a harmful time or in a harmful way, or to 
