CLEAR STREAMS AND BUILD I Isi-PassEs. 319 
York and the vast West, especially those waters running 
northward and eastward, all of which may, with a trifling ex- 
pense, be made alive with shining shoals ef the mighty sal- 
mon and the beautiful speckled trout. 
Tt is also important to assist the propagation of other food- 
fishes by artificial means. Legislatures should appropriate 
sums for these pressing objects, which not only cheapen 
meats, but add to the variety of food a source of health as 
well as luxury, and so cheapen it as to bring it within the 
means of all. 
Next in importance to artificial propagation is the purify- 
ing of rivers from the numerous pollutions incident to a care- 
less procedure in manufacturing, where poisonous minerals, 
tan-bark, sawdust, ete., drain into the streams, instead of he- 
ing conducted away from them or consumed. Commensurate 
in Importance with the purification of the rivers are properly- 
constructed fish-passes, to cuable a salmon to surmount dams 
and falls to reach their spawning-pools at the heads of streams, 
for without such means procreation can not go forward, and 
of the first stock few may be taken in the same river, but 
the greater number will seck more accessible spawning-beds 
at the heads of other rivers. 
Of the numerous reasons in favor of artificial propagation, 
the following are not the least important: 
Tt has been proven by experiment that of salmon not more 
than one in a thousand hatched naturally arrive at maturity. 
Of trout, it is probable that double that proportion mature, 
for the present experiment of propagating trout and salmon 
side by side in Australia proves that trout thrive best, and 
are what Lord Dundreary would eall “the most wobust.” 
But the ranks of the speckled beauties in our trout-streams 
and ponds have been eliminated, and require filling up. This 
can not be done without the assistance of art. Let us sup- 
pose that a pond which is supplied by streams suitable for 
spawning 1s stocked with five hundred trout, cach of which 
weighs a pound. In the course of one season they will de- 
