Preface. 



When in 1909 the last number of Volume I of the "Macrolepidoptera of the World" had appeared 

 some critics expressed a doubt as to whether an undertaking of such magnitude could be carried out on 

 the scale of the first volume. 



The friendly, even enthusiastic, reception accorded to Volume I has decided the fate of the entire 

 worij. From that moment there was nothing to hinder a rapid publication, and both editor and publisher 

 have strenuously endeavoured to carry out the plans set forth in the preface to Volume I. 



As the principal item in our programme was comprehensiveness, we have attempted, as far as the 

 limited space would allow, at least to indicate all that is of value in determining and classifying the species, 

 as well as to mention biological details. Frequently also remarks have been added which have reference to the 

 relation of the Lepidoptera to the environment, food, protective measures, injuriousness, etc. Although the 

 size of the present volume has hereby been increased, the volume containing 100 pages more than its pre- 

 decessor, the number of parts has nevertheless been restricted to thirty, as some of the parts consist of 

 several sheets of text. It has thus been possible to conform to the wishes of collectors desiring a compre- 

 hensive work on the hybrids of Sphingidae from the pen of the most experienced writer on this subject. 



The second point mentioned in the introduction to Volume I was rapidity of publication. The 

 financial question for the entire work having been solved by the reception accorded to Volume I, it was 

 possible to publish as rapidly as time would allow. The praiseworthy and strenuous efforts of the publishers 

 enabled us to issue no less than 488 parts since the publication of the first volume (Nov. 1909), viz.: 



Pale arctics Exotics 



46 German I 102 German I 



80 French parts 120 French / parts 



32 English 1 108 Englisli I 



which, for about three years (940 working days) works out at not quite two days for each part. Although 

 I do not anticipate that there is anybodj^ who does not appreciate such a performance, I hope nevertheless 

 that readers will remember the rapidity with which the work was issued if any slight errors of omission and 

 commission have escaped our vigilance. 



We have been blamed by some reviewers of our work for not going beyond our original intention 

 of providing a comprehensive handbook for collectors and Lepidopterists by examining the collections of Mu- 

 seums and private Entomologists for new species and by continuing the subdividing of forms and the naming 

 of aberrations already more than sufficiently carried out by others. We accept this reproof with the reserv- 

 ation that we did not follow this course on account of expediency, but because we as.sumed that the majority 

 of readers would not be pleased at the introduction of numerous new forms and the minute subdivision of 

 old ones. 



I cannot leave this subject without attempting to explain why another wish, which was more gene- 

 rally expressed, had to be ignored. Since the conclusion of Volume I nearly 150 weeks ago (Nov. 1909) almost 

 exactly 150 parts have been issued in each language; m the German edition, for instance, parts 56 to 102 

 of Division I and 41 to 143 of Division II, i. e. one part in each language every week. Why, we are asked, 

 is not a German part issued regularly every Monday, a French one every Wednesday, ^and an English one 

 every Friday, and why are periods of extreme haste followed by pauses of weeks or even months ? 



