l(j [January, 



CAUSTIC POTASH AS AN ENTOMOLOGICAL DETERGENT. 

 BY W. F. H. BLANDFOED, M.A., F.Z.S. 



Every student of Coleoptera, whose interest in the subject extends 

 beyond the recently captured contents o£ his own and his friends' 

 store boxes, is painfully aware of the trouble, hindrance and vexation 

 due to the dirty and mouldy state of many important examples which 

 he is called upon to examine. Save for a few most carefully kept 

 collections, every large accumulation of beetles contains hundreds of 

 specimens, none of which presents any intellip;ible characters until it 

 has been laboriously cleaned and restored as nearly as possible to its 

 original condition. 



Fortunately, this can be accomplished more satisfactorily with 

 beetles than with insects of any other Order, and so innumerable ex- 

 amples survive which would have disappeared by gradual decay, 

 or been thrown away had they belonged, say, to the more delicate 

 Lepidopfera. 



A dirty insect may owe its condition to one* or more causes, of 

 which the principal may be considered — 



Original Dirt, existing on the insect at the time of its capture, 

 never removed, and becoming more difficult to remove with lapse of 

 time : thus, the Histers, Aplwdii and other scatophagous beetles are 

 often besmeared with their source of nourishment ; wood-boring spe- 

 cies may have the recesses of their elytra clogged with the dust of 

 their burrows ; some Hydradephaga, Georyssus, Lacon, many Weevils, 

 some TenehrioniddB, &c., have their sculpture partly or completely 

 obscured with a crust of mud, earth or particles of sand. 



Grease. — This affects a large number of species, for example, 

 Qeodephnga, CoccinelUdce, Prionidce, wood borers and Phytopliaga. 

 Sometimes, by spreading internally, it changes the colour of the speci- 

 men, testaceous and pale markings being very apt to disappear in 

 certain Families. Sometimes it forms a crust on the outside, which 

 conceals the surface colour, particularly if metallic, or exudes in fatty 

 drops, which with lapse of time become opaque and waxy, and very 

 difficult to remove. 



Mould. — This does not appear on insects kept in a suitably dry 

 place, but many old collections which have undergone vicissitudes, and 

 those kept in the damp, particularly in country houses and near the 

 sea, suffer terribly, and may have scarcely an example free from it. 

 Beginning as a rule on the antennae, it spreads over the body, clogs 



