i66 



ON THE PLACE OF FIGURES IN DESCRIPTIVE 

 ENTOMOLOGY. 



B}' Louis B. Prout, F.E.S. 



It is matter of common knowledge among lepidopterists that 

 Monsieur Charles Oberthür has for years been strenuously 

 advocating the view that a figure or picture of the butterfly or 

 moth is not only a desirable addition to the diagnostic matter by 

 which a new species is made known, but a sine qua non ; indeed, 

 not only a sine qua non, but the sine qua non. And it is as a 

 natural outcome of that strenuously advocated view that the 

 present Congress is asked to consider the passing of a law refusing 

 validity to any new name which is not accompanied by a " good 

 figure." As the question — particularly in the aspect which is 

 presented by M. Oberthür's treatment of it — is one of consider- 

 able gravity, and some of the important issues raised have not, 

 or scarcely, been discussed in public, I feel it incumbent on me to 

 offer a small contribution to the subject. 



It is perhaps almost superfluous to say, at the very outset, 

 that the question is purely impersonal, and that if I am compelled 

 repeatedly to refer to M. Oberthür by name, and to his own work, 

 this is only because he and it are the embodiments of the principle 

 which is before us for consideration. I am above all things solici- 

 tous that nothing which I may have occasion to say, either here 

 or elsewhere, shall seem to detract from the esteem and admiration 

 which I feel for that prince of lepidopterists, and for his exquisite 

 Etudes. The position is a rather delicate one, as the proposal 

 which I have to attack is so dear to the heart of my friend ; 

 but I am emboldened by the eminently sane attitude which he has 

 taken in his correspondence with me on this matter, and I am 

 sure I am guilty of no breach of confidence, if I quote from one 

 of his letters, in order most heartily to endorse the view — that 



