PROBLEMS FOR SCIENTIFIC SOLUTION. 73 
different periods of their existence, and according to the 
peculiar characteristics of the locality in which they may 
happen to exist, should prove a task of great delicacy and 
difficulty. It is not necessary, nor would it be possible, 
to enter fully into this question here; but so much depends, 
in salmon legislation and administration, on an accurate 
knowledge of the natural history of the fish in all its 
phases and varieties, and so much can be gained by an 
interchange of experience between different countries, that 
the importance of the question cannot be too strongly 
insisted upon; and the service which artificial culture 
of salmon can render in this matter can hardly be over- 
estimated. 
Another such point, in which the aid of artificial breeding 
can be called into requisition, is the case already referred 
to of the supposed death after spawning of the Columbia 
and Fraser River salmon. This question is eminently 
worthy of complete investigation, and could easily be set 
at rest, if by no other means, at least by the expedient of 
marking the fish artificially spawned before they are re- 
turned to the river. If only two or three of the fish from 
which the spawn is taken artificially were found in sub- 
sequent years, the fact would at once disprove the theory 
that the salmon of the Pacific coast invariably die. Or a 
few of the spawned fish might be retained in an aquarium, 
where the fresh water was gradually replaced by salt water, 
to reproduce as nearly as possible the conditions under which 
the fish would naturally exist on its downward migration— 
if it really does migrate. Or some of the eggs, transported 
to this country and artificially hatched, would produce fry 
which might be marked and placed in some of our rivers, 
where their movements might be watched to see whether 
the shorter length of our streams increased their power to 
