388 



are, as a rule, dried up to a considerable extent, or completely so ex- 

 cept for the "horseshoe ponds," which are remnants of an old bed of 

 Spoon River. 



3. Beck's Swale and connecting Ponds. — This small swale and 

 connecting marsh-land parallels the river in a narrow strip for most 

 of the distance between the Isabelle Township ditch and the C, B. & 

 Q. R. R. Station at West Havana. The ponds on Beck's land, just 

 south of the old Illinois Central bridge, are all small, the largest not 

 over 100 ft.X30 ft. They are connected with the township ditch by 

 the swale at high water. 



4. Schulte's Field and neighboring Marshes. — An overflowed field 

 of about 50 acres, owned by J. C. Schulte, lying between the Isabelle 

 Township ditch and the C, B. & O. tracks, about half a mile west of 

 the river. This area was cultivated previous to 1900, and even now 

 crops of grass are taken from it in late summers of moderately dry 

 years. In April and May the water is one to two feet deep over the 

 field. Similar land in the immediate vicinity brings the total acreage 

 available here as spawning grounds in normal seasons up to approxi- 

 mately 200 acres. 



Many of these marshes are newly made — the result of rise in river 

 levels due to drainage canal water — these bottoms having been culti- 

 vated fields previous to 1900. They are now overflowed throughout 

 the spring season and usually till the first or middle of June to a depth 

 of six inches to three feet or more. During this period there are 

 usually large variations in water levels in the marshes ; and towards 

 the close of the spring freshet season, there are likely to be rather wide 

 and sometimes sudden fluctuations in Avater levels and temperatures. 



5. Head of Flag Lake, northwest Shore. — One hundred acres or 

 more of "flag", smartw^eed, and willow-s. Bottom generally rather 

 sandy; depth of water, i to 3 feet, April and May, 1910 and 191 1. 



6. JVest Shore of Thompson's Lake, Warner's Cut to Big Coz^e. — 

 A narrow strip, several hundred acres in extent, of shallow water, 

 I to 3 feet deep. Smartweed, pondweed, willows, and button-bush ; 

 the bottom mostly soft black mud, but in places there is considerable 

 sand. 



7. Dierker Lake. — A small lake, about half a mile long, just below 

 Matanzas Lake. Smartweed and willows along shores; mud bottom, 

 little sand. 



8. Sangamon Lake. — At the south end of this lake or "bay", 

 which is six miles north of Beardstown, are extensive mud flats, sev- 

 eral hundred acres in extent, covered with W'illows, cut-grass, smart- 

 weed, and i^ondweed (Potamogeton) ; also considerable hornwort 

 {Ceratophyllum). Depth of water. May, 191 1, i to 3 feet. 



