viii PREFACE 



of purely systematic publications on these Insects. Only those 

 have been included which contain material of sufficient biological 

 interest to require a reference in the text. All papers, however, 

 dealing with the larvae, life-histories or faunal studies, have 

 been included. With the exception of two or three which it 

 has been quite impossible to obtain, all the works listed have 

 been carefully read and studied by the author. References to 

 the Bibliography are given within square brackets. 



A complete scheme of classification down to tribes is given 

 in Chapter XIV. It is hoped that this, combined with a very 

 full account of those external parts which are of use in classifi- 

 cation, will make the book of value to systematists. For the 

 use of British entomologists, a chapter is included dealing ex- 

 clusively with the British species (Chapter XVIII). At the 

 request of several entomological friends, a short glossary of 

 biological terms has been introduced, for the use of readers who 

 are not biologists. 



In a previous volume of this series 1 , the author, Dr 0. H. 

 Latter, in dealing with the Insecta, selects three types of this 

 enormous Class for study. These are the Cockroach, the Dragon- 

 fly and the Wasp. The Cockroach has for many years served 

 the purpose of a "type" for the Insecta, in all general courses 

 on Zoology. Now there are three essentials which a "type" 

 for general use ought to fulfil. Firstly, it must be obtainable 

 without undue difficulty, and easily preserved for use. Secondly, 

 it should illustrate as generally as possible the morphology of 

 its Class. Thirdly, it should present a fairly typical life-history 

 for its Class. The Cockroach completely satisfies the first two 

 conditions. But it fails in the third, since it offers no illustration 

 of the very important phenomenon of metamorphosis, which is 

 associated with the great majority of the Orders of Insecta. It 



1 The Natural History of Some Common Animals, by O. H. Latter, M.A. 

 Cambridge, 1904. 



