ix] ACULEATE HYMENOPTERA 123 



excellent for subsequent examination. Should the pin 

 be inserted wrongly it is possible sometimes to strap 

 the wings down into good positions with strips of paper, 

 but sometimes no amount of ingenuity or patience 

 will get them to come right. The mouth parts should 

 always be displayed; and here care is necessary as 

 the mandibles are often closed very firmly over the 

 softer maxillae and labium, and in attempting to 

 separate the mandibles with a needle these more 

 delicate structures may easily be injured, and perhaps 

 the entire head torn away from the thorax. The legs 

 should, of course, be spread out from beneath the 

 body; and in the case of male insects the "genital 

 armature" extracted from the end of the abdomen 

 and rendered accessible to the magnifying glass. 

 Great care should be taken to allow the insects to 

 become thoroughly dry before removing them from 

 the "setting-cork " ; and it is necessary also to remove 

 from their bodies grains or perhaps masses of pollen 

 before placing them in the cabinet. This last opera- 

 tion is best performed with the aid of a soft paint- 

 brush, first cutting the bristles short so as to render 

 the brush somewhat " stubby." If these precautions 

 are neglected the specimens are very liable to become 

 covered with a growth of filamentous mould, and thus 

 ruined. A further safeguard against mould and animal 

 pests which are so difficult to exclude from a collection 

 of insects is afforded by pinning in the corner of each 



