230 COMMON TROUT. 



as 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 familiar instances 

 of this; and the minute flies, {Empedes,) which 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 spaAvning; and yet, in Cornvv^all 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 



