All those who, before the publication of his works, have had to 

 identify and classify exotic butterflies wiU fully appreciate the enormous 

 advance made by Fruhstorfer in this field. 



None of the species he has studied will need to be dealt with again 

 for many years to come. His main endeavour was to limit as far as 

 possible the use of the term "species", which is used in far too wide a 

 sense, and to identify and classify known species with reference to all 

 their geographical and seasonal variations. 



In the text of Seitz's great standard work he solved this problem 

 wherever possible, in the most brilliant manner. It is true that a few 

 mistakes and inaccuracies have crept into this text, but Fruhstorfer 

 can hardly be made responsible for these. They are mainly due to the 

 speed with which the editor — urged, perhaps, by a sad presentiment — 

 was endeavouring to get the work done. 



Such part of Seitz's work as has been successfully completed could 

 never have been produced in these days, — less than ever now that 

 Fruhstorfer has gone. 



So far as I know, he was also the first to make successful use, in 

 determining species, of the anatomical study of the male genital organs 

 of butterflies. 



Following the example of his eminent predecessor, Dr O. Staudinger — 

 by whom be was influenced more, perhaps, than he was himself aware, 

 but whom he excelled in acumen and penetration — he subsequently 

 sent out collectors on his own account to tropical countries. Thus he 

 sent collectors to the distant island of Engano in western Sumatra, sent 

 Sauter to Formosa and Dr. Werner to New-Guinea. 



He identified and described a large number of new varieties brought 

 from Formosa and thus went further even than the Japanese who want 

 to identify the Indo-Malayan fauna of that island with their own purely 

 palaearctic fauna. 



From his retreat in Geneva Fruhstorfer also turned his attention 

 to the Palaearctae and later to the Orthopterae, thus abandoning for a 

 time the study of his beloved butterflies. Even in that field of research 

 he did pioneer's work and acquired in a short time an astonding amount 

 of knowledge. 



Alas, he did not live to see the publication of his great work on the 

 Orthopterae of Switzerland which appeared shortly after his death. 



During the last year of his life, however, he contritely returned to 

 his beloved Lepidoptera and we owe to this renewed interest some exceed- 

 ingly valuable chapters on Malayan Lycaenidae in Seitz's work. They 

 represent an immense advance on the work of his predecessors. 



