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most favourable for this fly, which may be used 

 from eight o'clock in the morning till six in 

 the evening, and when they are abundant no 

 other fly will be taken." The artificial green- 

 drake is generally dressed on too large a scale, 

 which is the principal reason that many persons 

 do not think it a killing fly. It should never 

 be dressed on a hook larger than No. 9 Red- 

 ditch, or a No. 3 Kendal ; but the latter hook, 

 unless ordered expressly for the purpose, is too 

 short in the shank. It is of little use to fish 

 with the artificial green -drake, unless there be 

 a strong wind curling the water, and when such 



country appear at the very same time each year ; nay, fur- 

 ther, the very hour of the day at which they should rise 

 from the water into the air is fixed to such a nicety, that in 

 each succeeding day these swarms of insects come forth at 

 the precise instant at which they had appeared the prece- 

 ding day. No insect executes an operation (that of casting 

 its larval skin) at once so important and laborious, with 

 equal celerity. We do not draw our arms from the sleeves 

 of a coat more quickly, than the ephemera extricates its 

 body, wings, legs, and the long caudal appendages, from a 

 sheath in which these various parts are folded and cramped 

 up. We could hardly expect that an insect which, when 

 perfect, is so frail and delicate, could exert, in its imperfect 

 state, so much force as the act of getting rid of its larval 

 skin appears to demand. It would seem, however, that the 

 address and strength necessary to eifect its emancipation, 

 is supplied at the moment of need by a power independent 

 of the will of the insect. Swammerdam's experiments 

 prove, that every part of the body of the insect is in itself 

 capable of its full developement. He detached a wing still 

 inclosed within its larval skin ; it immediately unfolded 

 itself, and attained all the natural dimensions which it 



