PREFACE 



SO many great names are enshrined in the literature 

 of Insect Transformation, that the publication of a 

 new book on the familiar theme may appear hazardous 

 if not presumptuous. And as with lapse of time the literature 

 accumulates, a well-balanced treatment of the subject becomes 

 increasingly difficult. In this volume designed to serve as 

 an introduction to the study of growth and change in the life 

 of insects the author has sought, while re-telling many 

 well-known stories, to call attention to some structural details 

 that have hitherto escaped mention in text-books, and to 

 discuss the relation of such details to the wider problems of 

 insect life-histories. He ventures, therefore, to hope that the 

 book may be of some service to serious workers in entomology 

 as well as to beginners. 



Descriptions of the form of adult insects are given only in 

 so far as is necessary to elucidate the structure of larvae, 

 pupae, and immature stages generally. No attempt has 

 been made to compile a bibliography, but references are given 

 to books and papers to which the writer is indebted, and 

 full lists of titles are to be found in many of these. 

 Especial acknowledgment is due to the writings of A. S. 

 Packard, L. C. Miall, L. F. Henneguy, J. H. Comstock and 

 R. J. Tillyard. 



The source of every borrowed illustration is indicated in 

 its title, and the thanks of the author and publishers are 

 rendered to the United States Department of Agriculture, the 

 Cambridge University Press, and the Royal Dublin Society, for 

 the loan of blocks. The Cambridge Press has generously 

 allowed the use of several figures from the author's " Life- 

 story of Insects," and from Dr. Tillyard's " Biology of 

 Dragon-flies," while Prof. J. H. Comstock has kindly granted 

 the use of illustrations from "The Wings of Insects," and 

 from his lately-published " Introduction to Entomology." 



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