Vlll PREFACE. 



" Teachers in science are nearly equally divided into two 

 classes ; — those who know too much and those who know 

 too little. Those of the first class, overloaded with science, 

 cannot admit the possibility of meeting with readers who 

 have none ; and therefore their essays and introductions are 

 so worded that it requires a tolerable proficiency to under- 

 stand them. The teachers of the second class fall into the 

 opposite error ; they curtail, garble and popularize the writ- 

 ings of others without understanding them, forgetful that it 

 requires a consummate knowledge of any science to abridge 

 a work which treats of it ably and at large. The author 

 submits, that both classes are in error ; he submits also that 

 introductory works should be written for those who know 

 nothing of the subject on which they read, and by those who 

 possess, in themselves, some practical knowledge of the sub- 

 ject on which they write." This entirely agrees with my own 

 feelings, that a person must have more skill in order to teach 

 the unlearned than would be necessary to teach those who 

 have already made some progress. 



It can hardly have failed to have struck the most unob- 

 servant that the votaries of Entomology have of late years 

 increased in a rapid ratio; this has become statistically ap- 

 parent in the recent development of the Entomological 

 Society. It is but a few years since I attended a meeting 

 for the purpose of devising some scheme of extricating the 

 Society from a position of considerable difficulty, it being 

 then 130Z. in debt, and with an expenditure in excess of its 

 income ! Many might have been tempted to despair of re- 

 covering the Society from so deplorable an abyss ; but John 

 Bull, however fond he may be of grumbling, never despairs, 

 and besides it is proverbial that " when things get to the 



