82 
MR. F. FAY ON THE LOCH-LEVEN TROUT. 
spots. As the water in the two localities was the same, food would 
seem to have been the principal reason of this change in colour. 
Although the last experiment does not prove very much, it 
shows that some alteration in colour may follow new environ- 
ments ; but a still more conclusive result as to the change in colour 
which may take place in these fish under like circumstances has 
lately occurred in Gloucestershire. The present proprietor of 
Cowley had two ponds in a wood on his estate, each about an 
acre in extent, and from the lower of which springs a small 
stream ; these he wished to have stocked with some good kinds 
of sporting fish. The two ponds are supplied by underground 
springs, while there is a fall of about 16 feet from the outlet of 
the upper poud, and a rather greater one from that of the lower 
where the stream commences. It will thus be apparent that no 
fish could obtain access from above, neither could they ascend 
the 16-feet perpendicular fall from the stream to the lower pond. 
It was determined to try the Loch-Leven trout; so these ponds 
were drained, mudded, and then puddled with clay. 
During December 1884 and January 1885 one thousand yearling 
Loch-Leven trout were received from Mr. Andrews of Guildford*, 
and these were placed in the ponds by Mr. Ogden, of Cheltenham. 
In August this year (1886)1 was informed that, it having become 
necessary to remove these fish to a more suitable locality, they 
had been capturing them, and very great differences were percep- 
tible both in size and colour among the two sets of fish — those 
in the upper pond being silvery with a few black spots, whereas 
those in the lower pond w r ere of a much larger size, covered with 
spots, and having purple and golden reflections. Having obtained 
leave, we visited these ponds on August 25, and first examined 
the temperature of the water by means of thermometers, when 
we found that they scarcely differed. The lower pond was the 
deeper, and in it w r ere large quantities of the American weed, 
Anacliaris Alsinastrum, also some Cliarct, while on the surface 
was a considerable amount of the water crowsfoot (Ranun- 
culus aguatilis)-, whereas in the upper pond there were fewer 
weeds, but some Fiinpinella Saxifraga was present near its upper 
end. 
* Mr. Andrews, of West gate House, Guildford, wrote (September 14,1886): — 
“ The yearling fish supplied to Mr. Ogden, of Cheltenham, in 1885, were Loch- 
levens reared from eggs which were sent me from Howietoun. There can be 
no doubt of their being from ova from Stirling, as they were put in a pond 
quite distinct from the others on a different water-shed.” 
