Preface. 



While the fourth volume of the German edition could yet be completed in 1914 and 1915, the out- 

 break of the World's War prevented the communication of the publisher and editor with the author, and 

 the English edition could only be brought to a finish after the resumption of the literary connection. 



This volume concludes the first principal part of the Macrolepidoptera of the earth comprising the 

 whole palaeartic range in which 15 444 species have been included, and a much greater number of which than 

 in any of the previous volumes are to be looked upon as a reproduction of butterflies that have never before 

 been represented in pictures. It was only by means of the water-colours painted in a thorough life-like style 

 by Miss Peotjt in the British Museum from the stock of the collections of Leech, Wileman and others, 

 that we were enabled to show pictorially many species of which only the type or very few specimens had been 

 known hitherto. 



With this volume the number of illustrations of the palaearctic part has been increased to 12 247, 

 which are more by 2247 than we had in view at first, and held out in our prospectus. Of course, by reason 

 of this extra performance, the number of parts, which was calculated to be fifteen, was also exceeded by 

 five in this volume; yet, owing to the greater completeness' offered in the illustrations, we hope to have 

 raised the utility of the work and also to have deserved the indulgence requested for the limits of the last vo- 

 lume with respect to the elaboration of the Geometrides. 



As to the text, which exceeds the initial program by ten sheets, we have, after exhaustive delibera- 

 tions with the author, Mr. L. B. Prout, above all taken the practical point of view into account, and abridged 

 the diagnoses as much as possible with coloured species that cannot be mistaken in the pictures, while forms 

 that are harder definable, as for instance the Boarmia, Gnophos, Acidalia etc, we have brought out in a 

 more detailed way. On the other hand, with some species, as for instance Medasina and others, an illustration 

 was not necessary in some isolated cases, when, according to specialists, coloured figiu'es would not have 

 rendered a material aid for their definition. Thus, for instance, with many Ewpithecia of confused minute 

 markings and great variation in the colouring, unenlarged pictures were declared to be valueless and even 

 misleading, and for this very reason great and richly illustrated monographs of this kind have renounced such 

 pictures. We, therefore, thought it more to the purpose to make use of the available space in such cases by 

 the combination of easily recognisable distinctions in the description and scrupulous statement of biological 

 and geographical details. We should like to point out that the irregularity in the treatment, devoting, for instance, 

 to the variegated and in the figure sufficiently recognisable Abraxines 2 to 3, but to the more difficult distinguish- 

 able Acidalias and Boarmias 10 to 20 lines, is but a specious one, and that contrary to the restriction to 

 what was necessary and indispensable consistency has been aimed at. 



Only the elementary descriptive list, which has to be looked upon as an addition not provided for 

 in the prospectus, was not yet completed at the outbreak of the war in 1914. The impossibility of obtaining 

 the more up-to-date foreign writings as a close control of the proofs, resulted in the absence of some of 

 these proofs. But they refer almost without exception to quite inferior and mostly insignificant aberrational 

 or secondary species, so that they will hardly be missed. 



We have willingly complied with the suggestion communicated to us from among the circle of subscribers, 

 prior to the completion of the fourth volume, also to put to the synonyms the reference to the pictures. 

 A double reference being saved thereby, we regret that this desire has not been made known to us before 

 the table of contents of the earlier volumes was finished. 



As the publications of new descriptions were very much facilitated on the issue of the separate chap- 

 ters of the ,,Macrolepidopteras" by the classification of what was already known, it was certain that within 

 the well-nigh 8 years from the appearance of these 4 volumes, many new specimens, hitherto difficult to define, 

 should be found and published. In order to instance one case, we may quote the profusion of the names of 

 „Parnassms'' that have been enumerated since 1907 — the year in which this chapter appeared in the ,,Macro- 

 lepidopteras". The danger, threatened in this way, by an obsoleteness of the first volumes before the com- 

 pletion of the work, had been anticipated, and we intend to safeguard the work against this danger by 

 an occasional edition of supplementary numbers, in which everything necessary to be known is to be supple- 

 mented in the text as well as by coloured plates, thus keeping the work always up to the mark. These supple- 

 mentary numbers will appear in loose sequence subordinate to the productiveness of new discoveries of the 

 different years. 



As intimated in the introduction to the earlier volumes in a work which by all means must be looked 

 upon as a first attempt as to its scope and arrangement, numerous defects are unavoidable. Many of them 

 might only have been avoided by a more careful and slower elaboration of the prodigious material, whereby 

 many faults would have been omitted and a more thorough penetration into the subject been produced. But we 

 have, as emnhasised again and again, not been desirous to admit a further rise of the price of the work 



