1870. | INTRODUCTION OF SALMON INTO TASMANIA. 751 
of the ova of Salmo trutta, which arrived in April 1866. These ova 
were kept in a separate hatching-box, and hatched in May following. 
Part of the fry were placed in the same pond with the Salmon-fry 
hatched that year; the residue were placed in a separate pond and 
rill constructed for them. In October 1867, more than half of the 
fry in the Salmon-pond assumed the smolt dress and went to sea, 
the gratings being purposely removed. In October 1868, all that 
were left of the fry in the Salmon-pond put on the smolt scales and 
left for sea. 
Of the fry placed in the other pond, a number assumed the smolt 
dress in October 1867, but were purposely kept back, in the hope 
that spawn might be obtained without the usual migration seawards. 
The smolts became very restless ; several threw themselves on to the 
banks and were destroyed; others died, and amongst them one 
which I preserved and have forwarded by this mail for preservation 
to the Society. 
In October 1868, all the fishes that were left in the separate pond, 
and which had not become smolts the year before, put on the bright 
scales and exhibited the usual restlessness. Again several died, and 
before the commencement of winter, in May 1869, the Commissioners 
lowered the water to make certain alterations in the pond, and found 
the fishes reduced in number to twelve, all of which were handsome 
silvery fishes, without the slighest trace of parr markings, and varying 
in weight from nearly half a pound to more than a pound. During 
June and July 1869, five spawing rids were constructed by these fishes 
in the rill attached to their pond. . The old fishes were then shut off 
from the rill bya fine wire grating, to prevent their interfering with the 
ova, which commenced hatching in September. In December 1869, 
500 of the fry from these ova were set at liberty in the River Huron, 
the remainder being retained to increase the breeding stock, and to 
ascertain whether the migratory instinct would recur in these fish. 
The fry so retained are now, at eight months old, the picture of 
health, and exhibit the brilliant orange fin from which the trivial 
English name of the parr of Salmo trutta is derived. One of these 
parr I have also forwarded for preservation to the Society. 
From the foregoing details it is manifest that, if the specimen sent 
to England was hatched from ova received in April 1866, that fish 
must have left our pond as a smolt in October 1868, and remained a 
year, either in the river or in the sea, without adding one inch to its 
length, or one ounce to its weight, while its brethren, unnaturally 
detained in fresh water, not only increased in size, but arrived at 
sexual maturity and deposited healthy ova. 
From Dr. Giinther’s letter it is clear that, if he had received the 
fish sent from a Scotch instead of a Tasmanian river, he would have 
pronounced it a healthy fish, as it might then have been a smolt of 
either 15 months or 27 months old without presenting any abnormal 
conditions ; and is it not quite possible that a few pairs of the 
smolts which went to sea in October 1867 may have returned to 
the river (as many British authorities hold they do) in the February 
following as breeding fish, which would deposit ova in June or July 
