I8s.:..j ^ 17 



the limbs, andjeventually covers the insect with a mass of hyphse till 

 its original form is lost, and it looks like a mass of dirty cotton wool 

 stuck on a pin. 



Dirt, accumulated on the specimens since their capture and ce- 

 mented by grease and mould, consisting of the floating dust of the air, 

 the debris caused by mites, or derived from such extraneous sources 

 as the box of a snuff-taking entomologist. 



Some old specimens present an indescribable mixture of grease, 

 mould and dirt, which at first sight appears to defy the utmost efforts 

 of the would-be cleaner. 



The ordinary methods employed for cleaning dirty specimens, 

 useful in their way, are inadequate when the deposit is unusually 

 formidable. Among them are grease solvents, as chloroform, ether 

 and benzine ; soap and water ; and alcohol of various strengths, some- 

 times with the addition of carbolic acid. 



The grease solveuig referred to are of great use in cleaning spe- 

 cimens of which the colours have been darkened by the flow of grease 

 inside'lthe body, a matter very often observed in CoccinellidcB ; the 

 insects are immersed in the solvent for foi-ty-eight hours or more, as 

 with greasy Lepidoptera, and then dried. They are also valuable for 

 restoring the appearance of a specimen with a tJdn deposit of grease 

 or dust on the outside, being applied with a brush. Even here they 

 are often unsatisfactory ; unless the internal grease has been removed 

 by immersion, they dissolve out fresh quantities, and as each applica- 

 tion of the liquid dries off, so does the surface become dull and spotted 

 again, requiring a fresh wipe with the brush and often defying any 

 attempt to clean it thoroughly. In such cases an almost dry brush 

 should be used, just moist enough to remove external dulness and not 

 to bring out fresh grease. 



This is the most convenient way of cleaning specimens which 

 have suffered no more than the ordinary deterioration due to a few 

 years' sojourn in a store box ; and of the various solvents, chloroform 

 is the most pleasant to use, is not inflammable, and (as Dr. Knaggs 

 has shown) most quickly dissolves the grease. But all these reagents 

 are useless for the cleaning of really dirty and mouldy specimens ; 

 they remove no more than the grease, and not always that if it has 

 become waxy with age. 



Soap and water, and alcohol with or without carbolic acid, are 

 employed when the insects are really dirty. They arc inadequate, and 



