METHOD OF RELAXING INSECTf. 321 



Those known species that are subject to grease, should have the 

 Contents of the abdomen taken out, and the cavity tilled with cotton. 



Tricuoptera, Neuroptera, IIymenoptera, and Diptera. — Most 

 of the Libellula: require the contents of the abdomen to be taken out 

 when the insert is dead, as the body generally turns black within, a 

 icw days after death, without this precaution : the cavity may be filled 

 up with a roll of white paper or cotton : I have found this method tn 

 answer extremely well, and the colours are as brilliant as when the in- 

 sect was alive. The larger species are very powerful, and when col- 

 lected they must be transfixed through the side and placed in the 

 corked pocket-box ; a brace or two should be placed across the wings, 

 to prevent their fluttering and breaking their wings or those of other 

 insects which may be near them. They may be killed by being plunged 

 in boiling water, or by a hot needle, as directed for Moths. The other 

 species of this Order not being so large soon die, as well as those of 

 the Orders Trichaphra, Hi/mertoptcra, and Diphra. They may be set by 

 braces and pins, as in pi. 11. jig. 4. In some species of the Diptera the 

 colours of the body are very lively, but change after death ; in these 

 the colours maybe i)reserved if the contents of the abdomen be re- 

 moved, and the cavity filled with a powder the colour of tlie living in-^ 

 sect. 



METHOD OF RELAXING INSECTS. 



It frequently occurs that insects become dead and stiff before the 

 Entomologist has an opportunity of setting or displaying their parts. 

 Cokoptern are easily relaxed by immersion in hot water; and in many 

 instances this way is to be preferred, as the parts liecome more pli- 

 able and are more easily set. — The Orthoptera, Ilcwiptcra, and Le- 

 pidoptern, must be fixed on a piece of cork, and placed In a pan 

 of water covered over; these, if the specimens are large, will fre- 

 quently require two or three whole days before the wings will admit 

 of replacing without the risk of breaking ; care must be taken not to 

 force the wino-s, or any part in fact, until the parts are perfectly re- 

 laxed when they may be displayed and kept so by braces, as directed 

 for recent specimens. Neuroptera, Hi/meiwptera, and Diptera, may be 

 relaxed accordino- to the latter method : but those insects that require 

 the contents of the abdomen to be removed, can never be altered, and 

 therefore must be preserved in a recent state, or their beauty is lost for 

 ever. 



