THE CANADIAN ENTOMOLOGIST 247 



marked off according to box numbers, so that immediate reference 

 can easily be made directly to any series. 



A beginning has been made of the study of genitalia, and about 

 six or eight hundred most excellent mounts have so far been pre- 

 pared by Mr. W. H. T. Tams. Where material and time have 

 permitted, several mounts of a species have usually been prepared 

 from one locality, and where variation has been noticed or sus- 

 pected, more have been made from different localities. As many 

 as four are sometimes put upon one slide, and each mount is num- 

 bered to correspond with one on the specimen from which it was 

 taken. These bear the usual data, and are carefully preserved, 

 being in many cases installed in the general collection, and their 

 position indicated by a special symbol at the side. The slides are 

 numbered consecutively, and a catalogue is kept of them, in which 

 brief, critical notes are entered. This study entails the sacrifice 

 of the abdomens of the specimens. Poor, if recognizable, speci- 

 mens have been used by preference, but when such details of com- 

 parison were thought to be of extreme value, good specimens have 

 often been used, even of rare species. It is confidently believed 

 that the partial spoiling of a certain number of specimens is a 

 means fully justified by the end in view, which is the ultimate bet- 

 ter understanding of a department of entomological study about 

 which, whilst much has been WTitten and suggested, a very great 

 deal yet remains to be discovered. So far as the author has at 

 present investigated, much valuable evidence, sometimes quite 

 unexpected, has been acquired. And though it is by no means 

 proposed to accept all previously published notes and figures made 

 by others on the subject as unimpeachable evidence in favour of 

 claims made therefor, certain facts brought to light speak for 

 themselves in such a way as to remove all doubt w^hich may have 

 existed as to the extreme value of the study, if carefully and in- 

 telligently followed, as an aid to the elucidation of various obscure 

 problems of relationship. 



Perhaps the most regrettable want in connection with the 

 collection is a good library. This contains very few publications 

 of an earlier date than 1890, and scarcely any European literature, 

 none of the earlier authors. 



