6 
———S 
thousand stomachs, representing about two hundred species. Hight 
hundred and eighty of these have now been exhaustively studied, 
and several papers giving the results of some of my recent investi- 
gations have been published in the transactions of the State Horti- 
cultural Society. Seventy pages of Bulletin 3 of the Laboratory 
were given to a full report on the food of the thrushes and the blue- 
bird, and a paper is now in progress for Bulletin 6, giving the 
results of an elaborate study of the relations of birds to the canker- 
worm, and to the oscillations of injurious insects in general. Sim- 
ilar studies are in progress on the food of the arboreal birds, and a 
report on this subject will be ready for the press before spring. 
4 
INVESTIGATION OF THE FOOD OF FISHES. 
The collections illustrating the food of fishes represent about fifteen 
hundred specimens, including nearly all the species found in the 
State. Half of these have now been exhaustively studied, and most 
of the results have been published in the Laboratory bulletins. In 
Bulletin 3 was an elaborate description of the food of the spiny- 
finned fishes of the State, and of the young of all orders. Especial 
attention has been given, during the last two years, to the food of 
the young whitefish—a subject of peculiar importance and difficulty. 
A careful study was made of the contents of the intestines of sev- 
eral hundred of the young fry sent me from the whitefish hatchery 
of the U. §. Fish Commission at Northville, Michigan, and the con- 
clusions thus reached were tested by experiments on the young, 
kept first at the Laboratory, and afterwards, to the number of sev- 
eral thousand. in a tank at the Exposition building in Chicago. 
These specimens were fed with an abundance of all the minute 
plant and animal life obtainable from the lake, and the kinds se- 
lected were determined by the dissection of large numbers of speci- 
mens made at regular intervals. The minute life of the lake has 
been thoroughly studied in this connection to determine the variety 
and abundance of food available for the young fishes at various 
places and at all seasons of the year. 
PARASITIC PLANTS AND ANIMALS. 
Work on this subject (added to the duties of the Laboratory by 
the Legislature at its last session), has already been partly de- 
scribed, as far as it relates to plants, under the head of field botany. 
The various collections of parasitic plants made by the botanical assis- 
tant, are in process of determination and description by him and by 
Prof. Burrill at Champaign, and the first of a series of papers on them 
will be published this year in the Bulletins of the Laboratory. Besides 
the collections made in the State, nearly four thousand species of 
named fungi (chiefly parasitic) have been bought, including all the 
exsiccati of Thuemen, Ellis, and Cook and Ravenel. | 
The necessary books have been obtained for a study of the para- 
sitic animals of the State, and measures have been taken for regu- 
lar supplies of material, chiefly from slaughter-houses in different 
parts of the State. These have not yet been received, however, in 
quantities sufficient to justify publication of the results. | 
