ELEVENTH ANNUAL MEETING. ial 
i 
derstood as meaning that I would reject an experience related by 
a brother fish-culturist which did not fully accord with my own, 
but wished merely to state that I clearly recognize the fact that 
4 naturalist should believe nothing that he hears and only half 
of what he sees. Heshould be in that state of mind which is open 
to conviction, but neither believes nor disbelieves. To those 
to whom it seems incredible that part of the sac of a trout ora 
salmon should be thrown off by a mighty effort of nature when 
found to be poisoned, I would suggest following my ex periment, 
if a blunder can be so called, and when the liver of the fry turns 
white, remove the fish into a clean, healthy trough and note the 
result. 
In this connection it has occurred to me that the reason that 
trout do not flourish below sawmills is on account of the water 
being impregnated with either pine or oak. In 1875 I lost a lot 
of California salmon at Blacksburgh, Va., in an oaken trough 
which one of the then fish commissioners of Virginia, in whose 
employ I was, insisted upon my using. The impregnation of 
tannin was perceptible to the taste, and the fry died as fast as 
hatched. The theory of the fishermen near sawmills is that the 
sawdust gets into the gills of trout and kills them. This may be 
true to some extent, but I doubt it, for the reason that sand or 
other material does not appear to injure the gills, and I have 
taken adult trout below sawmills. I incline to think that the 
mills are destructive merely to the young, by covering the 
spawning beds to some extent with sawdust, but more by the ab- 
sorption of turpentine from the pine, or tannin from the oak, 
the evil effects of which we know too well. 
The PresipENtT called on Col. McDonald to state what had 
been done in the way of retarding shad eggs with a view to 
transportation across the ocean. 
Cot. McDonatv.—The results of the experiments have shown 
that retardation cannot be carried beyond six days, in the case 
of shad eggs. In connection with Prof. Ryder I undertook 
to retard them by keeping them at a constant temperature, but 
it was late in the season, and the water was up to 75 degrees. 
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