PREFACE TO THE NORTH AMERICAN EDITION 



Harold Oldroyd, associated with the British Museum (Natural History), 

 is known throughout the world among specialists for his research work 

 on the classification of the blood-sucking flies, especially the horse flies 

 of Africa. Thus, it is a distinct departure for a speciahst in a particular 

 branch of science to write a semipopular book for general distribution. 

 While this book does have its technical points, the author has been able 

 to develop the technical aspects of the science of entomology by the use 

 of easily readable English. The format of the book also departs to a 

 certain extent from the generally accepted textbook version. Thus, the 

 book gets away from the "textbookish" tone that is so prevalent among 

 other books of this type. 



The changes which have been made in the North American version 

 are largely those of terminology. Where the original version uses common 

 British or European species of insects for examples, we have substituted 

 North American examples which would be more commonly known by 

 the North American reader. The estimated numbers of insects have 

 also been changed to bring the text in line with the North American 

 situation. English phrases and spelling, peculiar to the British English, 

 have not been changed, except where it was thought that it would be 

 more understandable by the North American reader. The book thus 

 retains its decidedly British ^az^owr. 



Roland L. Fischer 



Michigan State University 

 May, 1962 



