y [\[ 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 5 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 u when things get to the 
