274 THE ENTOMOLOGIST. 



of the funnel, is 1 in. in diameter.* The sieve itself consists of 

 perforated zinc with holes 1 mm. {^^ in.) in diameter. 



The total cost in stout sheet zinc with an iron stand was 

 a little over .£2 ; copper would be more lasting, but corres- 

 pondingly expensive. 



The measurements could, of course, be altered to suit 

 circumstances, and for general purposes one rather smaller 

 than the above, about 18 in. in diameter, would be most con- 

 venient, while one even smaller than this would be quite useful. 



The water in the funnel should be kept at a temperature of 

 about 105-110° F., when the greater part of the catch will come 

 through in the first twenty-four hours. If the raw material is 

 plentiful, it is best to put in a fresh supply at this point, but if 

 there is only a little of it to hand, or if it is for any reason 

 required to examine more thoroughly any one lot, it may be 

 left in several days. 



For ordinary purposes 70 % alcohol is the most convenient 

 material to put in the bottle, but any fixing fluid may be used, 

 while, if plain water be used many of the insects will remain 

 alive until examined. For this it is most convenient to turn it 

 out into a watchglass or shallow dish, and by examining under 

 a dissecting microscope, any desired specimen can be removed 

 with a fine pipette. 



A certain amount of rubbish or small particles of soil always 

 comes through the sieve, especially from such materials as soil 

 and peat, moss on the contrary giving practically none. 

 Almost anything that will go into the sieve may be examined : 

 soil, moss, garden rubbish, dead leaves, decaying wood, peat, 

 grass, seaweed, birds' nests, &c., while to give an idea of the 

 variety of material obtained, I may mention the following : — 

 Small worms ; shells ; woodlice ; spiders ; chelifers ; Acarids 

 (in profusion, especially Orobatidae) ; Miriapoda (Chilognatha, 

 Diplopoda, Symphyla, Pauropoda) ; Protura; Thysanura (espe- 

 cially Campodeidae) ; Collembola (in profusion) ; Aphaniptera 

 (from birds' nests) ; Thysanoptera ; Psocidse ; Aphids ; Psyllids; 

 ]3ymenoptera (ants, winged and wingless Chalcids, Prototripids, 

 &c.) ; small caterpillars ; Coleoptera (Staphylinidre, small 

 Carabidffi, Trichopterygidae, &c., and numbers of larvae); Diptera 

 (of all sorts, including wingless forms and numbers of larvae). 

 In fact, there is scarcely any group of insects of which repre- 

 sentatives are not at some time found. 



The John Innes Horticultural Institution, 

 Merton, Surrey. 



* Care should be taken that in the making there is no projecting inside 

 at the joint of the funnel and the tube, which would prevent things slipping 

 past into the bottom. 



