120 BEES AND WASPS [OH. 



to turn out all the specimens, now stupefied and 

 probably dead, and to wipe out the inside of the 

 tube with the net or handkerchief. The brief ex- 

 posure of the specimens to a free current of air is 

 usually sufficient to prevent a recurrence of the 

 deposit. Failing chloroform, the ordinary cyanide 

 bottle may be used, provided a wad of blotting-paper 

 has been inserted to prevent moisture from spoiling 

 the specimens. On really hot days no poison is 

 actually necessary, for the heat of the sun itself may 

 be employed to kill the insects : if the tube contain- 

 ing the captured specimens be laid on a flat stone or 

 on a patch of sand fully exposed to the sun's rays the 

 prisoner is very speedily killed. It is extraordinary 

 how very slight a rise of temperature is fatal to these 

 sun-loving creatures. I well remember finding on the 

 sand-dunes of East Norfolk many patches of sloping 

 sand at whose foot lay numbers of dead insects of 

 many kinds : the slopes all had a more or less southerly 

 aspect and were thus exposed to the full heat of the 

 sun. It required but a short period of observation 

 to find out the cause of these piles of dead : after 

 watching for a few minutes I saw a female Pompihis 

 plumbens running about and evidently on the hunt 

 for spiders: there being no danger signal to warn 

 her she chanced to run on to the fatal patch and 

 instantly sprang into the air, only to fall on her 

 back, dead of heat apoplexy. I then placed my 



