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DIPTEBA (TWO-WINGED FLIES). 
specimens, the ultimate condition of which, when so treated, is rarely 
as satisfactory as if they had been brought home alive in pill-boxes. 
If, however, it is necessary for any reason to dispense with pill boxes, 
and to use the killing-bottle in the open, a little crumpled tissue- 
paper should be placed inside it; this affords a lodgment for the 
specimens, and so lessens the risk of their being injured by rolling 
about. It may be noted that Anthracinse when placed in pill-boxes 
are very apt to injure their wings by buzzing about, and large Tabanicke, 
(Estridce, and certain other Diptera are liable to suffer in the 
same way. On the other hand, the hairy and scaly body-covering 
of Anthracinse is very easily rubbed off, so that if carried in the 
killing-bottle they must be treated with special care. It is always 
advisable when out collecting to carry a killing-bottle for use 
in case of need, in the event of the supply of pill-boxes running 
short. Diptera on windows may be captured in pill-boxes; if the 
edge of the box be slightly raised from the glass on one side, 
and a piece of thin card passed under so as to shut the ffy in 
the box, or a little tobacco smoke blown into it so as temporarily 
to stupefy the fly, it will be found easy to slip on the lid without 
allowing the insect to escape. 
Spirit not to be Used. 
Unless intended for dissection, Diptera must on no account be 
placed in spirit. Since all descriptions of Diptera have been based 
upon dried specimens, Hies in spirit have to be taken out, dried, and 
pinned before they can be examined and compared with descriptions. 
In drying, however, they invariably shrivel ; while immersion in 
spirit often causes colour-markings to disappear, and inevitably 
results in hairs, scales, etc., being washed off or matted. Specimens 
intended for dissection (as when it is desired to examinesome specially 
remarkable structure, such as the proboscis or genitalia) should, 
however, always be placed in a small tube of spirit, with a plug of 
cotton-wool on the top of them to prevent their being injured by 
washing about. Before being preserved in spirit (90 per cent, 
alcohol) specimens should be fixed by being brought to boiling 
temperature in a test-tube ot water, or preferably a mixtuie of 
equal parts of 90 per cent, alcohol (ordinary rectified spirit) and 
