INTRODUCTION 
Some possess barbules (as in the Barbel), others have 
none. Some have jaws alike on both sides, others are 
not alike, the mouth being situate at the end of the 
snout, or the snout protrudes beyond the mouth. Some 
have spines (as in the Sticklebacks), many, if not most, 
are spineless. Some have teeth, others are toothless. 
Some have horizontal bodies, in others the body is 
vertical. Some have the upper and lower sections of 
the tail equal, others have the tail uneven, one lobe 
being larger than the other. Some have a cylindrical 
form, others (as in the Flat Fishes, such as the Plaice), 
have the body flat and unsymmetrical. 
Of the variety of colour and markings it is not possible 
to enlarge, nor of the many other features of interest 
regarding the external differences that exist in even our 
comparatively few fresh-water species. The examples 
that have been given will be amply sufhcient to reveal the 
interest to be obtained from a study of these tenants 
of our lakes, lochs, streams, rivers, brooks, burns, and 
ponds, and when it is stated that in one item at least 
they are certainly all alike, namely, in the possession of a 
vertebre, or skeleton, we must pass on. 
The angler soon discovers that some fishes are shy and 
retiring, but that others are bold and pugnacious. Some 
are ravenous feeders, others are very fastidious in regard 
to their diet, and manner of procuring same. Some are 
tender-mouthed, others have strong jaws which, although 
sadly interfered with on occasions, does not seem to 
unduly upset the finny owner. 
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