54 iNSTRIJCTtdNS FOU 



No. 23, used for the smaller species, but, as a rule, specimens which 

 are small enough to require this size are better pinned with a short 

 pin, and then staged. No. 20, a short, very fine pin for small flies, 

 gnats, etc. Nos. 10 and 5 are degrees stouter. 



An ounce of No. 20 pins (7s. 6d. per ounce) contains about 

 3,750 pins, but these short pins can be obtained in quarter-ounce 

 boxes. An ounce of No. 1 6 contains 320 pins. 



Gum. — For gumming small insects on card some entomologists 

 use gum-tragacanth, as it is not conspicuous ; but it has the 

 great disadvantage of being very difficult to wash off. Gum-arabic, 

 with a veiy small quantity of powdered loaf-sugar and one or 

 two drops of glyceiine, is perhaps the best mixture. If pure 

 gum-arabic is used, the insects are liable to spring off. The 

 sugar and glycerine prevent this ; but the latter must l)e used very 

 sparingly, as it has a tendency to attract moisture, which is one of 

 the entomologist's greatest foes. For some purposes, Le Page's 

 liquid glue (Russia (Jement Co.) is invaluable. Some entomologists 

 use McCaw's seccotine, a very similar preparation, which has the 

 advantage of being sold in metal tubes, so that it is portable. 



Card. — A hard white card or three- or four-sheet Bristol board 

 should be used. 



Rou7id Punch. — This should have a diameter of about | inch for 

 cutting out circles of card the use of which is explained further on. 

 A 20-bore gunwad-punch answers well. 



Larva-preserving Apparatus. — This consists of spirit-lamp, small 

 oven, and inflator. Instead of an oven a piece of copper gauze 

 placed over the flame of the spiiit-lamp answers very well. The 

 whole apparatus can be obtained from entomological agents. 



Collecting. 



Besides those which may be caught on the wing with a butterfly- 

 net, insects should be looked for on flowers, under bark of trees, in 



