How to obtain it. 273 
have previously been unacquainted, but on being compelled by 
hunger to eat it afterwards become ravenously fond of it. 
In cases where trout have absolutely refused some (to them) 
new kind of food, and it has not been expedient to break them on 
to it by hunger, I have done it by mixing a little and increasing 
by degrees, and then diminishing the quantity of the old food, and 
they have thus been beguiled into eating the new. It is quite 
evident that they have their likes and dislikes, as is shown by 
their rejection of one bait whilst they eagerly take: another. 
Domesticated trout are fond of frog tadpoles, but dislike those of 
toads. There is a foetid odour about toads which does not exist 
on frogs, and the trout can at once tell the difference. It is quite 
probable that the sense of smell has much to do with this as well 
as taste. 
The great variety of colour and marking which exists amongst 
trout must have struck everyone who has had much to do with 
them. There are many influences at work, each of which pro- 
duces its own variety. Then, again, the blending of these influences, 
and their consequent colouring, the crossing of different races, 
hybridism, age, sex, good or bad breeding, migration, season, 
food, surroundings, bottom, and last but not least the quality as 
well as quantity of the water itself, to say nothing of exposure to 
light or otherwise. All these and many other influences are at 
work, making up an innumerable number of varieties, many of 
which have been regarded by the older naturalists as distinct 
species. 
Trout may be briefly divided into two kinds, viz., the 
anadromous, or sea-going, and the fresh-water forms. Both are 
more or less migratory, and therefore the terms “migratory” and 
‘“‘non-migratory,” which have been so often used, are not 
altogether correct. Even some of the so-called fresh-water kinds 
are known to go to sea occasionally. 
The question as to how many species of trout exist in Britain’ 
is one that has evidently puzzled the ichthyological writers of the 
past. The tendency has been to increase the number of species 
as new types or races were discovered, and very naturally so, 
considering the knowledge that was then possessed. But fish 
culture has put a new phase on the subject altogether, and we are 
T 
