Srewart.—On the Introduction and Acclimatization of the Salmon. 207° 
were made for the use of a fine stream of spring water, rising in the woods 
to the eastward, and on the opposite side of the lade, or canal, from which 
the works draw their water. The pipes from this spring were not, however, 
laid when that season’s stock of ova was deposited in the boxes, filling, I 
think, 276 of them and leaving twenty-four empty. The frost set in with 
severity before the spring-water—which had a constant winter temperature 
of about 45° Fah.—could be turned into the filtering-pond, and the boxes 
began to freeze. Immediate steps were taken to cover them with hurdles 
and straw, and with the rough woollen blankets used by the fish-merchants 
in despatching their salmon packed in ice to the London market. Before 
this was accomplished, however, two lines of boxes were frozen to the gravel, 
and were soon shapeless masses of ice. The frost lasted one month, and, 
in the thaw, the ice in these two lines of frozen boxes was broken up into 
lumps, in which the ova were seen retaining their natural appearance. 
Such an opportunity for experiment was not to be overlooked. The lumps 
of ice and imprisoned ova were deposited in the water of the boxes which 
had not been stocked. From the protected boxes, 252 in all, much ice, con- 
taining more frozen ova, was gathered and put with the rest, all of which 
quickly thawed, and the eggs were found in the gravel presenting a perfectly 
healthy appearance. The result was, the ova, which had been frozen during 
one month, was one month longer in the incubation, and, so far as I remem- 
ber, produced just the same proportion of fish as the others which were 
kept above the freezing point. It was then remarked that, if the ova would 
keep safely in solid ice during one month, they would most likely do so for 
three or four, and so solve the problem of transit through the tropics. 
Although I am not aware of this circumstance having been remarked by 
writers on the subject, I notice that, in one instance, it is taken for granted 
that the freezing of the ova for a few days, or at most for a few weeks, is 
certain destruction to its vitality. It will most likely be found to depend on 
the period at which they are frozen. In the case mentioned the weather had 
been freezing from the date of spawning ; but not with severity sufficient to 
freeze running water, so that, practically, the process of incubation had not 
commenced. 
The possibility of, by this means, transporting healthy ova to the 
antipodes, became so familiar to my mind, and I judged it to be so well 
known, that when the (I believe) first attempt was made to effect it in the 
ship “ Beautiful Star” in 1862, and failed, from the length and generally 
unfavourable voyage causing the ice to give out, I attributed it to the method 
of solid freezing having been ignored. 
It is sufficiently proved, however, that the method of packing in moss 
and ice, and stowing in an ice-house, is capable of preserving the ova in 
