14 
us, by a critical and exhaustive study of the environment, to 
find the materials for rational hypotheses as to such causes, 
and to test such hypotheses by experimental procedure. It is 
thus always the field observation, or the laboratory observation 
made under conditions which involve the least practicable depart¬ 
ure from natural conditions actually existing, which must pre¬ 
cede and suggest the experiment. The method and the general 
object of this work resemble thus more closely, on the whole, 
those of the agricultural experiment station—which is, indeed, 
a biological station under another name and devoted to a spe¬ 
cial end—than those of the laboratory of experimental physi¬ 
ology ; and it is because ours is to be in the end and in its 
final objects a station for the solution, by experimental methods, 
of both special and general problems in the field of oecology 
that it was christened by its official board of control the Biolo¬ 
gical Experiment Station of the University. 
EQUIPMENT. 
The main features of our present equipment are the labo¬ 
ratory boat and its contents, the steam launch, a number of 
skiffs, and the apparatus and belongings of the Illinois State 
Laboratory of Natural History and of the biological depart¬ 
ments of the University of Illinois, both of which are placed, 
without restriction, at the service of the Station force. 
THE FLOATING LABORATORY. 
Our ultimate objects do not limit us to any single field, but 
will eventually compel us to transfer at least a part of our oper¬ 
ations to other points for purposes of comparison and contrast. 
Indeed, the Illinois River work is but a convenient point of 
departure for an investigation of the whole Mississippi River 
system. These facts have made necessary for us a movable 
construction of considerable size, carefully designed and 
thoroughly equipped for our work. Furthermore, the great 
changes of water level and the enormous expansion of the area 
covered at flood in the region over which we operate, would 
make a location on shore oftentimes extremely inconvenient as 
working quarters for our Station force. There is a great ad¬ 
vantage also in a position in the very midst of our held, where 
contact with the objects of our interest must be almost con- 
