THE CANADIAN ENTOMOLOGIST. 



1. Place the specimens (except the hind wings, which should not be 

 treated thus) in a dish containing some of the potash solution. This 

 substance disintegrates the muscular and other body tissues quite rapidly, 

 but affects the chitinous framework on which our classifications are based, 

 but very slowly, though the dissolution of enclosed pigments renders the 

 hard parts more transparent. The objects must remain in the potash 

 until they are sufficiently softened to permit of the muscular debris being 

 removed easily and the chitin rendered fairly clear. In many instances 

 this will require but a lew hours, or ii may take several days, the length 

 of time depending on the thickness, solidity and -pigmentation of the 

 dissection. The true way of judging is through experience, which is soon 

 gained. Ordinarily considerable latitude may be allowed the time of 

 immersion, a few hours mere or less making little difference in the 

 majority of cases. The mouth pans of most beetles should be soaked at 

 least twenty-four hours, the legs somewhat longer, while the mandibles 

 and elytra are still more refractory. If it is desired to hasten the process 

 the solution may be kept warm, but on the whole it is preferable to carry 

 on all operations at the natural temperature of the room. 



2. Take the specimens out of the potash and lay them in a dish of 

 clean soft water. By pressure with the finger tip carefully squeeze out the 

 fluid remains of the internal organs, muscles, and so on, being particular 

 to direct the discharge through a natural opening or through one of the 

 orifices where the member was amputated. Place for a short time in 

 another dish of clean water to get rid o( most of the remaining potash. 



3. Change the dissections to a dish of commercial alcohol. The 

 hind wings may now be added and carried through the rest of the stages 

 along with the other pieces. Leave in the alcohol for at least several 

 minutes, or until some convenient time when the next change may be made. 



4 Remove to absolute acohol. This is for the sake of getting rid of 

 all traces of water, since future successes depend largely upon thorough 

 dehydration. Give the specimens plenty of time, several hours if con- 

 venient, since no damage arises from prolonged immersion. 



5. Transfer the parts to clearing fluid. Let them remain in this for 

 several hours, since in thick specimens the process of permeation is slow. 

 Thin structures will clear in a few minutes, but if the work is hurried the 

 balsam is likely to be clouded when the object is mounted. 



6. Take one of the glass slips upon which the final mount is to be 

 made, and, after carefully cleaning it, place in the middle a large drop of 



