230 
COMMON TROUT. 
ns much as both the others taken together; although the 
quantity of food swallowed by them was in nowise so great. 
We think that the mingling of these sorts of food would have 
been still better; but it is known that the circulating juices 
or blood of many insects possess chemical properties very different 
from that of the higher animals; and the influence of which on 
creatures which feed on them must be stimulant as well as 
nutritive. Cantharidine in a species of beetle, a strong acid 
in ants, and ammonia in millepedes are liimiliar instances 
of this; and the minute flies, (Empedes,) M'hich in a winter’s 
gleam people the sunbeams, would be frozen to death if their 
blood were not composed of a fluid more powerful in resisting 
cold than a mixture of milk and water, or the blood of a mouse. 
But the young Trouts soon scatter themselves through the 
river, and everywhere shew themselves ready to take a bait or 
rise to a fly; but ready also to be scared by any passing object. 
In this indeed their course is often remarkable; for they will 
remain without fear close to the wheel of a mill while it is 
dashing round, and the water falls in a cataract; and they 
will even spring towards it when alarmed; but the sight of the 
human figure or other moving object will terrify them greatly. 
The Trout does not recover its health and appearance very 
speedily after spawning; and yet, in Cornwall at least, it has 
not unfrequently been caught with a fly in good condition in 
January and early in February; but it is probable that these 
examples had not shed the roe at the usual season, as is the 
case also with, at least, the Salmon; and it may be such as 
these which have been found ready to perform this natural 
function early in July; as we have known them. 
Nilsson appears to think it strange that the Trout is never 
in the open sea in the Baltic, while so many other fresh-water 
fishes are known to leave the rivers and pass into it; but this 
remark will not apply to the Trouts of our own streams, which 
have been noticed many times in the month of May to be 
quitting the river for the deep Atlantic. To satisfy myself of 
this I have procured an opportunity of having them taken in 
the salt-water with a net; and a well-grown Trout has been 
brought to me, that was caught at a considerable distance from 
a river or fresh-water. Under such circumstances a material 
alteration takes place in the colour of the fish, which becomes 
