Notes upon the Breeding of Salmonide, read at a Meeting of the 
Ootteswold Club, March 22nd, 1887. By Francis Day, 
C.I.E., F.L.S., etc. 
The following observations on the “Breeding of Salmonide”’ 
are a continuation of some which I laid before this Society on 
two previous occasions. Having been furnished by Sir James 
Maitland, F.L.S., from Howietoun, in December, 1885, and 
February, 1886, with a plentiful supply of eggs from his 
Lochleven trout, I have been enabled to investigate several 
questions, in addition to those which I have previously treated 
of. For fish-culture is a subject wide in its scope, and in it 
many statements have obtained unlimited credence, the cor- 
rectness of which I have considered it might not be amiss to 
test, and while the results have in most cases corroborated 
received opinions, in others they have yielded doubtful or even 
adverse conclusions. 
In my notes I have briefly considered the adaptability or 
the reverse of fresh waters to fish-culture, some of the pollu- 
tions which are commonly perceived, the effects of temperature, 
the amount of moisture or depth of water in which these eggs 
may be incubated, and what is probably necessary in order to 
obtain strong and healthy young, also the employment of salt 
water or the results of concussion on the ova. I have likewise 
touched upon some of the injurious forces which may affect 
the embryo when within the egg, and what influences may 
tend towards the survival of the strongest. 
The first deleterious agent which I propose remarking upon 
is cold, for although it is evident that in a modified form it is 
beneficial when present during the incubation of the eggs of 
these fishes, still in an intense degree it may be highly injurious 
to them, and even occasion their deaths. If we examine the 
geographical distribution of the Salmonide we see that with 
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