4 
Under the head of general zoology comes my own personal study — 
of the food and feeding habits and structures of several families of our 
fishes,—to which much time was given in the winter of 1887—88,— 
and the preparation of a general summary and discussion of the 
whole series of papers on this topic published by me since 1880. 
Minor labors in the same general field are a study of the species 
of harvestmen (Phalangide) of Illinois by Mr. Weed, on the 
anatomy and histology of certain crustaceans of subterranean habit 
by myself, and on the leaf mites of the State by Prof. Garman. 
Entomology. 
The entomological work of the past two years has been almost 
wholly economic in its objects, but incidental to the study of insect 
injuries to agriculture, a considerable mass of information and ma- — 
terial has been accumulated, of more general entomological interest. 
The purely economic work has been extraordinarily heavy and 
exacting, due especially to a wide-spread and very destructive out- 
break of the chinch bug, now but just disappearing. We have kept 
the infested area, both in southern and northern Illinois, under in- 
spection during the whole two years, making repeated visits to 
selected localities for comparative observations in the field. At Edge- | 
wood, in Effingham county, and at Tonti, in Marion county, we have 
conducted field experiments for the protection of wheat against 
chinch bug injury—in the former instances with great success, in the 
latter with only partial results, owing to the winter-killing of the 
grain. At the office we have made numerous tests and. experiments 
with insecticides. | 
During the summer and autumn of 1888, we have collected a 
very large amount of information from every part of the State con- 
cerning the effect on the chinch bug of different crops and combin- 
ations of crops, with especial reference to wheat culture, and have 
collated, tabulated, and discussed this information, deriving from it 
important practical generalizations with respect to farm management 
during the progress of a chinch bug uprising. 
We have also diligently studied three forms of contagious dis- 
ease to whose virulent activity in the southern part of the State is 
chiefly due the rapid disappearance of the larger part of the chinch 
bug hosts infesting that region,—a difficult and laborious research 
which is still in progress. 
| Next to the chinch bug, the Hessian fly and the corn plant louse 
