VI 
PREFACE. 
Our readers will best be able to judge the attitude of this work towards the methods of denomination, 
from the fact that whilst the index embraces some 5000 names, barely 100 denote new denominations that 
have been made in this Volume. Of these a number represent re-denominations that had become nomen- 
claturally necessary. 
Just as in the case of the text, we have endeavoured in the plates of the Supplementary Volume 
to bring everything up to date. Such illustrations that had not turned out satisfactorily, have now been 
replaced by better ones and in other cases, where 20 years ago only a description could be given, we are 
now able to supply the illustration. A comparison of the new plates of the Zxjgaena and those in Volume 2 
of the Main Series will show the improvements and advances in technical art during the last 2 decades. 
In regard to the illustrations, it lias been possible by carefully utilising the space at our disposal 
to concentrate same on to 16 plates. The editor has sought to achieve the golden mean between the pro¬ 
fessional zoologists, who would prefer to have no coloured illustrations at all. or only a very minimum 
of same, and the “magazine enthusiasts”, who would like a fresh illustration to show every minute variation. 
Experience has shown, that so far as Lepidoptera are concerned unillustrated works of reference scarcely 
serve their purpose; on the other hand such works that go to the opposite extreme, as for instance Verity's 
magnificent work, "R li o p a 1 o c e r a P a 1 a e a r c t i c a" have proved to be impracticable; it had to be ab¬ 
andoned on completion of the Papilionidae and Pieridae and after the final 20 plates had been issued in 
black and white, i. e. uncoloured. Illustrations on such a comprehensive scale would also not haVe been 
feasible in our Work. A simple calculation shows, that had we proposed to give a similarly extensive number 
of illustrations as Verity, we should have required at least 1500 plates for our palaearctic Volumes, whilst 
actually we have compressed the illustrations of same, including the Supplementary Volumes into abt. 300 
plates. Thus through its moderate cost and our system of instalments, we have made our Work available 
to every small club, every Institute and Scientific College and besides to the great majority of private 
collectors. 
As to the illustrations themselves, it has never been our intention to make a work of art of them. 
I therefore pass over such criticisms as that the shaft of the antennae is too thick, or the club of same too 
compact, or that the head is not quite the right shape and many other minute differences. There is a limit 
to the exactitude of reproduction and quite apart from the cost, it seemed more important to expedite 
the completion than to delay same by a pedantic insistence on trifling corrections. The greatest possible 
care was exercised to reproduce natural typical specimens and only very few of our illustrations are made 
from copies or sketches, as in such cases we were unable to control as to whether same were true to nature. 
In reproducing specimens by means of photography, as we have done wherever it was possible, one cannot 
avoid transmitting small changes in the shape (as for instance if a specimen has been rather too tightly 
compressed in its paper transport wrapper) and these cannot alw'ays be corrected in an illustration. We 
consider such irregularities to be unavoidable and are certain we may count on the indulgence of our readers, 
who will appreciate the general execution of our illustrations and their trueness to nature, both in regard 
to drawing and colouration. May we ask those that feel induced to criticise, to consider, that in a work 
with more than 50 000 illustrations, it is impossible for every single figure without exception to be perfect. 
In regard to various other points that would help our readers to understand the difficulties of plan¬ 
ning and publishing the Macrolepidoptera, I would refer to the Prefaces of the previous Volumes 
already completed. We are constantly being reproached that the compilation of the individual paragraphs 
does not in some cases cover the entity of an individual species. Often this seems to be merely an attempt 
to demonstrate some immaterial inexactitude or to establish the superior knowledge of our critic. The 
question of the relationship of forms and species to one another, with our insufficient knowledge of the 
exact biology in so many cases, is one that still requires much elucidation. It would often be actually 
impossible to make a definite assertion in these matters and to enter into an argument on such a subject 
in a work of this nature, would have been a digression that would have served no purpose. Our object is 
to make our work as complete as possible and to give all material details and references in the most succinct 
and concise form. 
It has been an anxious task for the editor to succeed in publishing the 48 parts, that have been 
issued during the year 1933 in accordance with the original scheme. Thanks to the untiring efforts of the 
publishers, this has been achieved and this is all the more creditable, as the difficulties that have been en¬ 
countered seem to have growui almost from day to day. The desperate state of affairs in the world of 
finance hinders the smooth liquidation of international commercial obligations. The interchange of goods 
between one country and another is now so difficult that trading has almost been brought to a standstill. 
The chaos in the exchanges is equally harmful to all nations and obstructs all progress. Even the necessities 
