between liigli- and low-water conditions in the Station field 

 is well shown by several of the plates appended to this re- 

 port.* This long-continued low water worked marked changes 

 in the topography of the bottomlands adjacent to Havana. 

 Phelps Laket^ dried up earlier than it did the preceding year, 

 Thompson's Lake showed a marked diminution, principally at 

 the northern and southern ends, long stretches of soft mud or 

 matted vegetation in which dead fish were abundant l)eing 

 exposed. This mud, after a few weeks exposure, hardened 

 and cracked open to a depth of a foot or eighteen inches, and a 

 growth of shore grasses began to spring up on it. Quiver Lake, 

 especially along the west shore and in the region known as 

 Dogfish Lake, was considerably reduced in area, and in the 

 absence of any considerable amount of vegetation its depth was 

 decreased more than usual. Flag Lake, which in most years is 

 a marsh with one to four feet of water filled with rushes, arrow 

 leaves, water smartweed, water-lilies, and the lotus, dried .up 

 early and a wagon road was established across its bed. Havana 

 Lake, the expanse of the river above the mouth of Spoon Eiver, 

 presented the unusual appearance of a narrow river channel 

 fianked on either side by a broad mud bank. The filling in and 

 extension of these banks by the deposit of silt during recent 

 years has been very marked, and is followed by an extension of 

 the swamp willows over the rising bank's. 



In a general way the hydrological conditions of 1898 

 resembled those of 1897. The rise of the river began in .Janu- 

 ary and continued through the winter, culminating April 2 at 

 eighteen feet, a point equaled or exceeded but twice since 1879, 

 at which time records were begun at the Government dam at 

 Copperas Creek, eighteen miles above the location of the Station, 

 As in 1897, the high water continued during the early summer, 

 dropping rapidly in August to the minimum stage. It did not, 

 however, reach the extreme condition of the previous year, several 

 minor fluctuations having occurred at frequent intervals during 

 the fall months. The reduction in the aquatic vegetation begun 

 in the previous year has continued. The increased activity in 

 the fishing industry has also contributed largely to the removal 



*For these localities see Plate I. 



+Oomiiare Plates III. and IV., and V. and VI. For differences with respect t<» mid- 

 summer vegetation at similar stage of water, see Plates VII. and VIII. 



