TROUT-FLIES. 93 
flies, as it loses all glossiness and strength of colour. 
For convenience in tying them several different thick- 
nesses of sewing silk are requisite, from ordinary sewing 
silk—which is of the proper thickness for small flies—to 
silk of about the substance of holland thread, which is 
the size most suitable for lake flies. 
All flies should be carried in a box, instead of being 
pressed together in a book, a process which robs them 
of half their elasticity and play of hackle, and to which 
they should never be subjected even for a moment. 
This is a most important point. Tackle makers think 
that the fly regains its full elasticity as soon as it is wet, 
but I have convinced myself by repeated practical ex- 
periments that this is not the case. 
SELECTION OF FLIES. 
SIZE. 
It is a curious fact, but nevertheless an indisputable 
one, that the size of the flies to be used in any given 
river or lake generally depends, within certain limits, not 
upon the size of the fish, but upon the size of the water, 
modified by the condition of the wind and sun. There 
are occasional exceptions to this rule—as to most others 
—hbut in the absence of local knowledge or guidance, 
which on this point is often useful, the fisherman 
acting upon it will find himself right in nineteen cases 
out of twenty. 
In most Trout streams, properly so called, in either 
