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some dragged on an existence longer than others, in fact, until 
the embryo was sufficiently grown to be examined under the 
microscope, but even in these, small black eyes were present, 
which are so distinctive of young deficient in vitality.* The 
heads also were found to be but indifferently developed, and it 
is reasonable to conclude that this must have been occasioned 
by the shock which their systems had received from cold. It 
has been observed by Dr J. Davy that salmon eggs will resist a 
great degree of cold, and such as is sufficient to freeze the 
water and imbed them in ice; but if so, this can only be when 
such is continued for a short time, as it has been demonstrated 
by M. Pouchet, that whenever a vertebrate animal is completely 
frozen, it cannot be resusitated, for its blood becomes disor- 
ganised. 
Exrrrmment No. 1.—To still further elucidate this question 
respecting the effect of cold on the embryo within the egg, 
on January 19th, 13 trout eggs were transferred from tray No. 
1 toan unglazed flower-pot saucer, some water having been 
added they were placed out of doors to freeze. 20th, 9.30 a.m., 
the upper surface of the water was frozen, but there was still 
some fluid below the ice, so it was left out of doors until 
8 p.m., when the eggs were enveloped in a solid block of ice. 
It now snowed but was still left out. 22nd, 5 p.m., looks the 
same. 23rd, again covered with snow. 26th, 9.30 a.m.,a thaw 
has set in, and all but three eggs still remain in a solid block 
of ice, but they look opaque and white, but were left to thaw 
out gradually; at 1.380 p.m., 9 were thawed out and still living, 
and by the evening 8 more, so 12 were transferred to tray No. 
7, one being found dead. Here 2 died on February 24th; 1 on 
March Ist; 3 on the 2nd; 2 on the 8rd; 1 on the 5th; and 2 
on the 7th. Thus all died within 47 days of their having been 
first placed in the saucer to freeze. 
® It has been remarked at Howietoun that insufficiently fertilised’ eggs 
may be primarily divided into (a) those wherein the embryo develop small 
and very black eyes, and (b) into such as have eyes of the ordinary size, but 
of a pink colour. The first of those classes being deficient in vitality was 
that which almost invariably showed itself in the embryos in those ova that 
survived sufficiently long for such to be apparent. 
