xii AUTHOR'S PREFACE 



Roder, Hoym (Anhalt) ; C. Verhoeff, Bonn ; W. Wustnei, Sonderburg 



(Alsen). To these gentlemen I here offer my renewed thanks. 



On the other hand, the records of flower visitors are not taken from 



works which deal with the flower pollination of a definite, circumscribed 



region. The following are among these. 



Hermann Muller, Alpenblumen (Leipzig, 1881), 



P. Knuth, Blumen und Insekten auf den nordfriesischen Inseln (Kiel and Leipzig, 



1894), 

 J, MacLeod, De Pyreneeenbloemen en hare bevruchting door insecten (Ghent, 



1 891), and 

 J. MacLeod, De bevruchting der bloemen in het Kempisch gedeelte van Vlaanderen 



(Ghent, 1893 and 1894)^ 



The observations set forth in these writings are, for the most part, 

 only referred to in this handbook, and the flower visitors that are recorded 

 are only indicated by reference to the chief groups to which they belong. 

 These books are necessary for every student of flower pollination, to 

 supplement the facts narrated in this handbook. 



The extraordinarily heavy and lengthy task of editing the lists of 

 visitors was undertaken by D. Alfken of Bremen, with praiseworthy 

 readiness. He has had the pleasure of receiving help in this work from 

 the following gentlemen. 



H. Friese in Innsbruck (Bees), 



F. KONOW in Teschendorf (Saw-flies), 

 R. Krieger in Leipzig (Ichneumons), 



G. KtJNNEMANN in Oldenburg (Beetles), 

 V. VON Roder in Hoym (Flies), 



A. Schletterer in Innsbruck (Digging- wasps), and 

 O. Staudinger in Dresden-Blasewitz (Lepidoptera). 



In writing the names of insects, Alfken has adhered to the rules 

 that were laid down in the proceedings of the German Zoological Society 

 in 1894 (p. 94), in which it is said (Par. 13d): 'It is desirable always to 

 write specific names with a small initial letter, following the example 

 of English and American zoologists.' 



In recent years much attention has been paid to the subject of 

 synonymy in the names of insects. It has, however, not been possible 

 for me always to accept the newer names, which are justified by the 

 researches of recent years, and therefore are now the commonly used 

 terms in entomological works, in place of the older ones employed by 

 Hermann Muller, Loew, myself, &c. When the second volume of this work, 

 which preceded the first volume, was in course of preparation, the naming 

 of insects was not conducted in conformity with a definite plan, and the 

 matter was still under discussion. 



* ' The Flora of Dumfriesshire,' by Scott-Elliot (Dumfries, 1896), also deals with flower visitors, 

 and these, again, will only be indicated in the present work. 



