The mounting of insects (which are naturally semi-transparent) without pressure has always appeared to me to be a far more satisfactory method than the process so generally in use, viz., the soaking the specimen in liquor potassæ until clear, and then pressing it flat between two glass slips. The liquid partially, or wholly, destroys the internal organs, and the flattening process completes what the liquid failed to accomplish; that is, in so distorting the insect that the flattened skin on the slip but very remotely resembles the natural insect.