152 THE SCOTTISH NATURALIST 



a folded sheet of clean white blotting-paper, and since this 

 forms a soft pad, while many of the dead flies when emptied 

 out of the killing-bottle fall naturally on their sides, it is 

 an easy matter to pierce them in the proper place without 

 lifting them from the paper, and sufficiently deep to penetrate 

 one or even both sides of the thorax. To hold the pins 

 securely either for the pinning operation or on any subse- 

 quent occasion a pair of well-made curved entomological 

 forceps is necessary, while for sliding the insect up the pin a 

 pair of fine straight forceps should also be used, closing them 

 on the pin (but not gripping it) near their points and below 

 the fly. By pushing the pin as it is held in the right hand 

 (by the curved forceps) between the adjacent points of the 

 fine pair, held in the left, the fly is gently and carefully slid 

 up into the desired position, and is then ready for " staging." 

 The staging operation, which is a necessity arising from the 

 use of fine pins (and advisable in all cases, even where the pin 

 is fairly stout), consists in pushing the fly-carrying pin 

 through one end of a small "stage" or carrier of cork or 

 other suitable material, while through the other end is pushed 

 a much stronger pin which is to be taken hold of whenever 

 the specimen is subsequently examined or in any way 

 handled. The mounts are made according to taste, some 

 workers using pith, " polyporus " strips, tracing gelatine or 

 celluloid, but the best and most reliable consist of oblong 

 pieces of cork cut for the purpose from the thin sheets sold as 

 "cabinet cork." The sheets should first be covered on the 

 upper side with dull, white paper, not too thick and not too 

 hard on the surface. A thin printing-paper serves the 

 purpose well, as it is of a soft texture and holds well with 

 good paste. The sheet of cork should have the paper 

 thoroughly well pasted down, not gummed, and then left 

 under a moderate weight for about twenty-four hours, after 

 which it can be cut by means of a thoroughly sharp flat- 

 bladed knife and a flat ruler into strips of various widths. 

 For the sake of future appearance it is best to adopt a fixed 

 scale of widths, say 8, lo, and 12 millimetres. These strips 

 are then to be cut transversely into narrow pieces, which 

 should eventually measure 8 x 2, 10 x 3, and 12x4 millimetres 



