I 
INTRODUCTION. 
I Fourth Report.] 
To His Excellency, John L. Beveridge, 
Governor of the State of I llinois : 
Sir— I herewith transmit my fourth annual report upon the injurious 
and beneficial insects of the State of Illinois. 
In this report I have carried out the plan proposed in the introduc- 
tion to my last report, of continuing the work there commenced under 
the title of Outlines of Entomology, so far as to complete the order of 
Coleoptera or beetles. As stated in the introduction just referred to, my 
object in this undertaking is to simplify and facilitate the study of this 
extensive and difficult science, for the benefit of those who may be in- 
terested in it, and who, it may be presumed, will comprise a considera- 
ble number of the young people of the State, under the stimulus recently 
given to the prosecution of this class of studies by the legislative enact- 
ment which requires that the study of natural history shall constitute 
one of the branches of education to be taught in the public schools. 
The continuation of this work, however, so as to embrace all the 
orders of insects, would require more time and study than could be de- 
voted to them consistently with the proper discharge of the more directly 
practical duties of this office. 1 shall not therefore attempt to continue 
~~ it any further, at least for the present. But as the study of the several 
orders of insects is, to a great extent, independent of each other, the 
present work, it is hoped, will be found equally useful to the student, 
so far as it goes, whether the remaining parts ever be completed or not. 
With the view of making the part now published as complete in itself 
as possible, I have appended to it a glossary of the scientific terms 
more commonly used in descriptive entomology, and also a list of the 
principal authors, in this branch of science, both European and Ameri- 
can. 
As the present report is a continuation of the preceding, or third an- 
nual report, and will undoubtedly fall into the hands of many who will 
be unable to procure copies of the other, I have reprinted, with some 
alterations, the concluding portions of the last report, which forms a 
natural introduction to the present. 
