8 INTRODUCTION. 



paper. The banks of streams, ponds, and lakes arc 

 good localities, and many species are to be found in 

 such places, especially under stones. The Water 

 Beetles {Di/tiscidce, &c.) live in ditches and ponds, 

 and must be caught with a water-net. The largest 

 captures may be expected when the water is high, as 

 the collector will then be able to take home portions 

 of plants from the brink and examine them at his 

 leisure. 



HOW TO KILL BEETLES. 



There are various ways in w^hich beetles may be 

 killed. The simplest method of dealing with dark 

 beetles, or those which are smooth and shining, is to 

 drop them into a bottle of weak spirits of wine and 

 water ; but this is inadmissible for hairy species and 

 for those which have a red colour. For these the best 

 contrivance is the follovvino; : a wide-mouthed bottle is 

 taken, and in it is inserted a bung, perforated to receive 

 a (Aass tube closed with a cork. In the bottle are 

 placed small pieces of blotting-paper moistened with 

 a few drops of sulphuric ether. The reason for this 

 arrangement is to prevent damaging the w^ing-cases by 

 friction, and the better to benumb and kill the beetles. 

 It is not good to use too much ether, lest the specimens 

 be moistened and spoilt. Bottles are sometimes charged 

 with cyanide of potassium ; whilst some collectors use 



