It might be of some interest, therefore, to put forward some remarks to which the study of the hypopygia of fungus gnats gives rise, these being supplementary to a paper published this year in the "Tijdschrift voor* Entomologie". First of all it should be stated that in this particular case the examination of the hypopygium offers little difficulty. Generally the hypopygium can be prepared in a very simple way, while some species even show the specific characters without any preparation.

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... some minutes' boiling in diluted caustic potash sufficed to remove every trace of desiccation and shrivelling. Then the hypopygia were transferred through water and 96 % alcohol into Venetian turpentine and mounted in the usual way between two small pieces of coverglass, so that they might be examined from either side. Regarding the preparations thus treated, the chief argument of the adversaries of hypopygium study, viz., the very dissimilar aspect of the organ in different positions, was done away with. For, in nearly all genera this treatment made the hypopygia lie on their ventral or dorsal side, only a slight movement round a transverse axis being possible. To be sure, in some genera the hypopygium tends to take a position on one side, but this is either not inconvenient in these special cases or can be prevented by the use of very thick turpentine. Of course, this simple method will not do in genera like Allodia, in which a more elaborate dissection is indispensable, the hypopygium being too complicated to be depicted in one figure. It seems to the writer of the utmost importance, however, that with the In spite of the many discussions on this subject, both in literature and meetings of entomological societies, a considerable controversy exists between those entomologists who, for determination, readily resort to a comparison of the hypopygia, this being too often the only part of the insect offering satisfactory species characters, and those who consider this practice beneath the dignity of scientific entomology. As it happened that the writer in the course of several years had to do much work on Fungivoridae, he had ample opportunity to become familiar with this problem.