VI 
PREFACE. 
the cost price of the work too high. Of the gigantic Zeuxidia only about 20 per cent, of the known forms were 
illustrated, but of the small Lycaenidae often as much as 60 per cent, of the denominated races appeared, because 
the former are easily recognized from the descriptions, whereas the subtile distinctions in the small lepidoptera 
necessitated a greater number of diagrams, and these did not take up too much room. 
As the composition of the Hesperids, completed in 1914 after Fruhstoreer’s plans, had remained 
unprinted until 1927, waiting for the preceding Lycaenids, the question arose whether it should be remodelled 
and brought up to date by additional annotation, or whether it should be printed in its original form. The 
reason why I decided to have it printed almost as it stood is that a properly revised version would no longer 
have corresponded to the plates, which were finished long ago. Also, the increase of material since 1914 did 
not seem to be great, and if all the forms studied since that year had been appended without omission, the 
composition of the Hesperids would have been out of all proportion with the other part of the work. Moreover, 
the time has already come to begin a Supplementa for the whole work, so no appreciable delay is caused 
by recording these new discoveries in this supplementary volume. Only those larger publications which had 
come out before 1914 but which could not reach Germany owing to the blockade, such as Waterhouse and 
Lyell, and others, were used in the additional annotations. 
The extraordinarily great number of Indo-Australian forms described — the index contains about 
1 4 000 names — made it essential to shorten and condense the treatise as much as possible. On an average, 
only two or three lines were at our disposal for every form, and thus none of the textual explanations could 
exceed its scheduled length. Particularly the question whether single forms are entitled to be regarded as 
species could hardly anywhere be entered into any more than in the other volumes. Such decisions without 
argument on anatomical circumstances are but of little value, and detailed argument is here quite impracticable 
owing to the great lack of space. In many cases, the question whether a form is to be considered as a ,,local 
race' 1 of its geographically neighbouring form or as a ,,vicarious species" will to a certain degree be a matter 
of opinion and cannot therefore be discussed here. We limit ourselves to collecting in paragraphs thoseforms 
whose differences admit of a general review; this rule will, in most cases, naturally 
assemble the different forms of one species (a so-called ,,total species") into one group, but this arrange¬ 
ment must not give the impression that all forms jointly dealt with are necessarily specifically related. 
Such criticisms, then, as this: - that certain forms being jointly quoted are ,,wrongly placed together", 
and so on, are to no purpose, excepting in those rare cases where this question is expressly mentioned by the 
author in the text. 
This cursory way of dealing with the forms only made it possible to condense the extraordinarily 
voluminous material of the Indo-Australian Rhopalocera in one volume. In spite of this, the suggested extent 
of the volume, 1000 pages and 150 plates at the most, was surpassed by 100 pages and 27 plates. It was 
therefore impossible from the very first to comply with the request of English readers to circumstantiate (and 
especially to illustrate by drawings) once more in Vol. IX the palearctic forms also penetrating into the Indian 
region, instead of merely mentioning them by references to Vol. I. I could not bring myself to do this, thus 
giving the opportunity of acquiring single volumes, to oblige readers who are specialists; the work in its entirety 
is meant to represent a whole factor, and I do not consider myself entitled, for the sake of single specialists, 
to make arrangements that would raise the price of the total work by the repetition of the text and illustrations, 
although this raise, as some subscribers write, would only amount to one or two dozen plates or a few pages 
of text. 
Ever since the work first came out, the question of nomenclature has always aroused the greatest 
interest in both specialists and laymen. When the work was just beginning, the discussion of the question resulted 
in a decision by the majority of zoologists to refuse to carry out the ,,International Rules of Nomenclature" 
as an obligatory codex. The editor’s opinion was, therefore, that owing to the scientific nature of the 
work, although it is dealing with exclusively entomological material, he should not deviate from the decisive 
standpoint of general zoology, by forgetting that entomology is only a branch of zoology. At the international 
congresses I was absolutely unconvinced that the ,,International Rules" would ever be carried out. Their 
inadequacy has been proved too clearly to allow any other opinion: not only have they failed to fulfil their 
principal task - of stabilising the nomenclature — but on the contrary they have increased the confusion by 
