66 THE SALMON FISHERIES. 
CHAPTER Vi 
Artificial Breeding of Salmon—Its advantages—Extensively adopted 
in America and Canada—Is it essential ?—Upper Proprietors and 
Salmon Angling—Scientific aspects of artificial Propagation—Non- 
migratory Sa/monide@—Classification of Salmon—Bull Trout versus 
Salmon—Study of Natural History—The Pacific Salmon Problem 
—Kippered Salmon—Natural Phenomena affecting the Fisheries— 
Legislation—Introduction of Salmon into Australasia—A glance 
into Futurity—Conclusion. 
THE opinion is gaining ground that, as it is to artificial 
causes that the deterioration of our salmon fisheries is due, 
so purely artificial measures should be resorted to in order 
to revive them ; that, instead of devoting all our energies to 
the restoration of our rivers as far as possible to their 
natural conditions, by remedying the obstructiveness of 
weirs, removing pollutions, and preserving the breeding 
fish, we should altogether supplant nature, and take the 
hatching and rearing of fish entirely into our own hands. 
Briefly described, the artificial rearing of salmon or of 
any other kind of oviparous fish consists in the following 
operations. The fish are caught when on the eve of 
spawning; a slight pressure causes the fully developed 
roe to escape from the ovaries—a process technically known 
as “stripping ;” the ova of the female fish, being placed 
in a suitable vessel, are covered with the milt of the male 
fish, and, the two being carefully mixed together, im- 
pregnation is effected. The ova are then washed, placed in 
trays or troughs, called hatching-boxes, through which runs 
a stream of cold water, under the influence of which, as in 
