PKOCEEDIXGS OF THE TIIIRn EXTOMOI.OCaC AT, MKETIXU !'51 



tbe ordinary cell inside the box is quite insufficient to j^revent the gi'owth 

 of jnould in such cases. 



When collecting, space in the store-box is often a consideration 

 and considerable economy can be effected by i^inning in the small speci- 

 mens (on small pins) first, when it will be found that a good many of 

 the larger specimens (on big pins) can be pinned in between and over 

 the smaller ones (Plate 150, fig. 2). In the case of large specimens 

 set out with their wings flat {e.g., butterflies, dragon-flics, etc.), 

 considerable economy of space can be effected by " shingling " them, 

 i.e., pimiing them into the box at an angle so that their wings overlap 

 one another. (Plate 151. fig. 1). 



Pins are made in various sizes and of various materials, the main 

 requisites being that they should be made of a hard, non-corrosive 

 metal, have sharp points and small heads, and be of slender diameter 

 and suitable length. Ordinary brass pins corrode sooner or later, the 

 body-juices of the pinned specimens attacking the metal with the forma- 

 tion of the so-called " verdigris," which is not verdigris at all but 

 copper butyrate. Silver pins are sometimes used for minute insects, 

 but are too soft and blunt and do not seem safe from corrosion. 

 The most satisfactory pins are those made from pure nickel wire. 

 We always use Messrs. D. F. Tayler's pure nickel pins, sizes 16 and 20, 

 the former being a stout pin 35 mm. long suitable for all large insects 

 and the latter a fine pin 15 mm. long suitable for all small insects. 

 These two sizes of piiis are suitable for all general collecting work. 



Sfagiiig is a method of mounting small insects, pinned with small 

 pins, to raise them above the level of the cork surface of the store-box 

 or cabinet drawer and to avoid injury when moving the sjaecimens. 

 The small pin of the specimen is driven into one end of the stage, through 

 the other end of which is passed a stout pin which bears the label and 

 is secured into the cork surface. The stage may be made of various 

 nmterials, of which pith and card are generally used. Polyporus pith 

 is very suitable as it keeps beautifully white and may be obtained in 

 square slips. Sola pith is obtainable locally and makes satisfactory 

 stages. Card is readily obtainable and may be cut to any size or shape 

 required and makes a good stage for permanent mounting. Double- 

 card stages are sometimes used in Em-ope, two similar card-stages being 

 used, one about an eighth of an inch below the other, and both large 

 and small pins being passed tlu-ough each stage ; but there seems to be 

 no special advantage gained by this method. Mica also is sometimes 

 used for staging, especially in the case of small Coleoptera, but I have 

 had no experience of it. Photographic film may also be used if a 

 transparent mount is desired (Plate 151, ^g, 2). 



