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IOWA ACADEMY OF SCIENCE Voi,. XXVII, 1920 
quarter is crossed diagonally by a creek which drains from the 
southeast to the northwest. In the summer only a small rivulet 
of water flows through this. But in the spring there is usually 
an overflow which inundates a considerable surface in this quarter, 
and converts it into a dry slough ; that is, one which is wet in the 
spring and early summer but becomes dry later. The slough 
grass in this area grows to a height of six feet, and is usually 
mowed for hay. The ground has never been cultivated. This 
uncultivated slough has an area estimated at about eighteen acres. 
The other three-quarters are practically alike topographically. 
There is no level stretch, but the surface is alternately high and 
low with gentle slopes intervening. These areas were under 
cultivation or used as pastures. 
Figure 63 is a diagram of the section as it was planted to crops 
at the time the survey was made, viz., July 25 and 26, 1916. 
Crops and Habitats . — The untilled portions of the section 
LEGEND 
■ RRM W 
M PO 
C CANE • 
a CLOSER + 
♦ Spring ® 
Willows 
POTATOES 
Hay-stack 
Marsh Hawk nest 
Burrowing Owl West 
Fig, 63. Diagram of the surface of the section studied showing the crop plantings 
and certain topographical features. In general, it also is a diagram of the ecological 
habitats of the area. 
