36 IOWA STUDIES IN NATURAL HISTORY 
swamp frogs and leopard frogs that abound in such places feed- 
ing on the myriads of winged insects that hover over the water 
and among the plants. 
On the map, no attempt has been made to discriminate between 
the merely boggy land and the swamp. Many of the smaller 
bodies, especially in Graham and Scott townships, will not re- 
main damp through the summer months, but their vegetation 
does remain different from that of the land about them in spite 
of excessive pasturage, affording a different association of insect 
life. Of the more extensive swamps of the county, all are fairly 
constant throughout the year. 
