PREFACE. 



structure, development, life-history, and other aspects of the 

 animal world which have points of contact with the life of 

 man. We have written for such as desire to study Insects on 

 this side. 



Whoever attempts to tell all that is important about a very 

 common animal will feel his dependence upon other workers. 

 Much of what is here printed has been told before. The large 

 number of new figures is, however, some proof that we have 

 worked for ourselves. 



It is a pleasant duty to offer our thanks for friendly help 

 received. Professor Felix Plateau, of Ghent ; Mr. Joseph 

 Nusbaum, of Warsaw ; and Mr. S. H. Scudder, of Cambridge, 

 Massachusetts, have very kindly consented to treat here of 

 those parts of the subject which they have specially illustrated 

 by their own labours.* Mr. E. T. Newton, of the Jermyn 

 Street Museum, has lent us the wood blocks used to illustrate 

 one of his papers on the Brain of the Cockroach. A number 

 of the figures have been very carefully and faithfully drawn 

 for us by Miss Beatrice Boyle, a student in the Yorkshire 

 College. We are much indebted to Dr. Murie, the Librarian 

 of the Linnean Society, for procuring us access to the 

 extensive literature of Insect Anatomy, and for answering 

 not a few troublesome, .questions. 



Five articles on the Cockroach were contributed by us 

 to Science Gossip in 1884, and some of the figures were then 

 engraved and published. 



In issuing a book which has been long in hand, but which 

 can never hope to be complete, we venture to adopt the 

 words already used by Leydig concerning his Lehrbuch der 

 Histologie : " Die eigentlich nie fertig wird, die man aber 

 fur fertig erklaren muss, wenn man nach Zeit und Umstiinden 

 das Mo^lichste orethan hat." 



o o 



* Prof. Plateau's chief communications will be found on pp. 131 and 159 ; 

 Mr. Nusbaum has furnished the account of the Development of the Cockroach, 

 pp. 180 to 195 ; and Mr. Scudder the Geological History of the Cockroach, chap. xi tj 



