116 COLLECTION AND PRESERVATION OF INSECTS. 



flies require to be pinned. Diptera and Hymenoptera 

 should, when sufficiently large, be pinned, like the Lepid- 

 optera, through the centre of the mesothorax ; Coleoptera, 

 through the right wing-case ; Orthoptera, through the pro- 

 thorax ; and Hemiptera, through the mesothorax, generally 

 in this class a triangular plate : dragon-flies should be pin- 

 ned in the centre between the four wings. 



All insects taken home alive in pill-boxes may be killed 

 thus. Open the lids of the boxes a very little way, just so 

 as to admit the passage of air, but not the exit of the in- 

 sect ; then make a pile of the boxes, thus partially opened, 

 on a piece of soft leather placed on a table ; invert a pint 

 basin over the boxes ; burn one or two matches under the 

 basin. If the basin and boxes are placed close to the edge 

 of the table, the facility of burning a match under the basin 

 is increased. The basin should be pressed down, and the 

 leather precludes the ingress of fresh air and the egress of 

 the sulphur-smoke ; if the boxes are examined in a few 

 minutes, the insects will be found perfectly dead. But it 

 must be borne in mind that the fumes of sulphur have dif- 

 ferent effects on different colours ; yellow and red retain 

 their brightness when submitted to it, or even acquire ad- 

 ditional lustre, but blues and greens, on the contrary, are 

 frequently totally destroyed. 



All kinds of insects are killed instantaneously by immer- 

 sion in boiling water ; and with the exception of Diptera 

 and Lepidoptera, none are materially injured by the process. 

 The minute insects brought home in quills may be readily 

 killed by immersing the quill in hot w^ater, at the same time 

 holding the cork between the finger and thumb. The bee- 

 tles brought home in spirits should be subjected to this 

 process, first, as a cleansing and purifying operation ; se- 

 condly, because the spirit appears only to stupify and de- 

 prive them of motion, so that without this second killing 



