FAUNA OF A SMALL BROOK 
863 
MACROSCOPIC FAUNA OF A SMALL BROOK. 
D. M. BRUMFIEL. 
INTRODUCTION. 
The brief paper here presented is but the first of a series of 
studies which the writer proposes to work out concerning the 
ecological relations of the animal life of Johnson county. John- 
son county has been chosen as the field for observations for sev- 
eral reasons, among which are its availability from Iowa City 
and the University buildings as a center, its wealth of diver- 
sified habitats, and the most excellent work already done by 
Professor Bohumil Shimek in the field of plant ecology, upon 
which all studies of animal ecology depend, as all animals ulti- 
mately depend upon plants for food. 
Any piece of work must have a beginning. The animal life 
of the small brook was chosen as an opening wedge to the larger 
subject because the brook represents the earliest stages of the 
development of a permanent stream in the reduction of the 
purely terrestrial habitats to the ultimate sea level water habitat 
by the process of erosion. Such streams afford the most favorable 
opportunities for study during the spring months. A further 
reason for the choice lay in the fact that the particular stream 
which receives the attention of this study lies within a few min- 
utes walk of the State University. 
The writer does not hope to introduce any new or startling 
facts. The fauna of the typical small stream has been surveyed 
and recorded many times and the various habitats with their re- 
spective associations of species which it affords have received 
treatment in Shelf ord’s Animal Communities of Temperate 
America. However, no extensive consideration of the anjmal life 
of the county could be considered complete without such a study 
and its present application to an Iowa stream may prove inter- 
esting to workers other than the writer. 
THE STREAM. 
The brook which is made the basis for this study lies within 
the city limits of Iowa City, although its valley lies outside the 
residence district. There are one farmhouse and three suburban 
