PREFACE. xv 
amongst diversities, and still more, the quick and accurate percep- 
tion of diversity in the midst of resemblances, constitutes one of 
the most important operations of the understanding ; if it be in- 
deed the foundation of clear ideas, and the acquisition of whatever 
can be truly called knowledge depends most materially on the 
possession of it;” if “ the best logic be that which teaches us to 
suspend our judgments ;” and “ the art of seeing, so useful, so 
universal, and yet so uncommon, be one of the most valuable a man 
can possess,” there can be no doubt of the judiciousness of their 
advice. Now of all the branches of Natural History, Entomology 
is unquestionably the best fitted for thus disciplining the mind of 
youth; and simply from these circumstances, that its objects have 
life, are gifted with surprising instinets admirably calculated to 
attract youthful attention, and are to be met with every where. It 
is not meant to undervalue the good effects of the study of Botany 
or Mineralogy; but it is self-evident that nothing inanimate can 
excite such interest in the mind of a young person as beings en- 
dowed with vitality, exercising their powers and faculties in so 
singular a way; which, as Reaumur observes, are not only alive 
themselves, but confer animation upon the leaves, fruits, and 
flowers that they inhabit, which every walk offers to view, and on 
which new observations may be made without end. 
Besides these advantages, no study affords a fairer opportunity 
of leading the young mind by a natural and pleasing path to the 
great truths of Religion, and of impressing it with the most lively 
ideas of the power, wisdom, and goodness of the Creator. 
Not that it is recommended to make children collectors of in- 
sects; nor that young people, to the neglect of more important 
duties and pursuits, should generally become professed Entomolo- 
gists; but, if the former be familiarised with their names, manners, 
and economy, and the latter initiated into their classification, it will 
be an excellent method of strengthening their habits of observation, 
attention, and memory, equal perhaps, in this respect, to any other 
mental exercise ; and then, like Major Gyllenhal, who studied 
Entomology under Thunberg about 1770, and, after an interval 
of twenty years devoted to the service of his country, resumed 
his favourite pursuit with all the ardour of youth, and is at this 
time giving to the world a description of the insects of Sweden, 
