vi PREFACE 



This book gives, of course with much greater fulness and detail 

 for reference and collateral reading, what we roughly outlined in 

 our class work. The aim has been to afford a broad foundation for 

 future more special work by any one who may want to carry on the 

 study of some group of insects, or to extend in any special direc- 

 tion our present knowledge of insect morphology and growth. 



Many of our entomologists begin their studies without any pre- 

 vious knowledge of the structure of animals, taking it up as an 

 amusement. They may be mere collectors and satisfied simply to 

 know the name of their captures, but it is hoped that with this 

 book in their hands they may be led to desire farther information 

 regarding what has already been done on the structure and mode of 

 growth of the common insects. For practical details as to how to 

 dissect, to make microscopic slides, and to mount and preserve 

 insects generally, they are referred to the author's "Entomology for 

 Beginners." 



It may also be acknowledged that even in our best and latest 

 general treatises on zoology, or comparative anatomy, or morphology, 

 the portion related to insects is scarcely so thoroughly done as those 

 parts devoted to other phyla, that of Lang, however, his invaluable 

 Comparative Anatomy, being an exception. On this account, there- 

 fore, it is hoped that this hiatus in our literature may be in a degree 

 filled. 



The author has made free use of the excellent article "Insecta" 

 of Newport, of Lang's comprehensive summary in his most useful 

 Text-book of Comparative Anatomy, of Graber's excellent Die 

 Insecten, of Miall and Denny's The Structure and Life-History of 

 the Cockroach, and of Sharp's Insecta. Kolbe's Einfuhrung has 

 been most helpful. But besides these helps, liberal use has been 

 made of the very numerous memoirs and monographic articles 

 which adorn our entomological literature. The account of the 

 embryology of insects is based on Korschelt and Heider's elaborate 

 work, Lehrbuch der Vergleichenden Entwicklungsgesehichte der 

 Wirbellosen Thiere, the illustrations of this portion being mainly 

 taken from it, through the Messrs. Swan Sonnenschein & Co., 

 London. 



