260 THE ENTOMOLOGIST. 



lack of it) of illustrations comparing the armature of different 

 species with each other. A few weeks ago I should have said 

 little or nothing on the subject, because I believed it to be im- 

 possible to produce anything which could be of practical value to 

 those who had not made a long and very special study of the 

 organs in question, and this in spite (or perhaps I should say 

 because) of the fact that I had seen the reproductions, and in 

 some cases the originals, of the photographs made by our most 

 eminent and successful micro-photogra])hers from the prepara- 

 tions of the most learned and painstaking of our microscopists 

 who have specialized in this direction. I have also in my 

 possession the original photographs taken by M. JuUien, of 

 Geneva, from his own preparations of the genitalia of this group 

 of the Melitaeas, three of which were shown at the first exhibition 

 of the Geneva Lepidopterological Society to illustrate the con- 

 nection between atJialia, deione, and berisalcnsis. All these are 

 far too complicated, in my opinion, to be of any considerable 

 value to the average entomologist who, without being a specialist, 

 is anxious to have a general working knowledge of all parts of 

 his subject so far as possible. Now, I am perfectly well aware 

 that m}' opinion as an individual has no particular value, but it 

 is just because I am not a specialist in this direction that I dare 

 to put forward a claim to speak on behalf of those who, like 

 myself, are merely interested students of fairly average intelli- 

 gence, and who have managed to reach a somewhat higher 

 entomological level than that of the very unduly despised " mere 

 collector." I would say, then, that the following points are 

 essential if such illustrations are to be of value to any but the 

 advanced specialist : — (1) They must all be in the same position, 

 and if in profile must be turned in the same direction ; ('2) the 

 preparations must all be made by the same person, for practi- 

 cally no two people make their preparations quite alike ; (3) they 

 must all be magnified to the same degree, and it will conduce to 

 further clearness if the photographs are all by the same photo- 

 grapher. This, until recently, was the utmost that I thought 

 might be hoped for, but far more has now been accomplished. 

 In the ' Bulletin de la Societe L^pidopterologique de Geneve,' 

 published this summer. Dr. Reverdin's and M. Charles Lacreuze's 

 illustrations of the genitalia of the Hesperids show how abso- 

 lutely intelligible such reproductions can be made in two different 

 ways. Not only have all the above points been carefully attended 

 to, but in both cases the armature, given in profile, is presented 

 with one side removed, so that only the essential structure is 

 shown without any unnecessary complications. The illustra- 

 tions to Dr. Reverdin's paper are reproductions of carefully 

 finished micro-photographs, those to M. Lacreuze's are much 

 more diagrammatic. For most purposes, indeed, it seems to 

 me that the more diagrammatic the illustrations the more gene- 



