64 



river had a decided influence on the abundance and variety of ani- 

 mals, both in the lakes and sloughs and in the river itself. It 

 will be referred to again. 



:ii£AK CREEK. 



This stream winds down through all the northern part of the 

 Illinois bottom-land, and after giving off several branches to 

 the Mississippi River on the west, reaches the upper part of 

 Quincy Bay, into which it formerly opened. At present the build- 

 ing of the Indian Grave levee across it, a short distance within 

 this mouth, has closed the outlet, and the only water discharged 

 into the bay passes through a sluice-gate. The lower part of the 

 <;reek is now, therefore, little more than a slough. This was well 

 filled with water when examined, and a small stream issued from a 

 break which, during a recent inundation, it had made in the levee. 

 The banks are steep, as a rule, as would be expected from the 

 alluvial character of the soil through which the channel is cut. 

 The shores are commonly wooded, and originally, doubiless, the 

 whole of the neighboring region was covered with forest. The 

 bottom is extremely muddy, and from the abundance of snags and 

 brush lodged in its channel and its stagnant water, it is not 

 an inviting collecting ground for the naturalist. 



BALLARD SLOUGH. 



This is a channel which has been cut obliq-uely across from the 

 Mississippi River to Bear Creek, reaching the latter about a mile 

 and a half northwest of the point at which the levee crosses the 

 creek. Its river end, covered by the levee, is a half mile further 

 north, and the length of the slough is probably not far from one 

 and a half miles. It was, when visited, quite shallow and extremely 

 muddy, and varied greatly in width at different portions, some- 

 times expanding into pools of considerable extent, and again con- 

 tracting to fifteen or twenty feet in width. It was not continuous 

 at this time, and probably during most seasons dries up in great 

 part before the close of summer. 



BARENESS SLOUGH. 



Harkness Slough is a channel which extends almost exacth' par- 

 allel with Ballard Slough, and lies a quarter of a mile further 

 south. It is verj' narrow, — not fifty feet across in much of the 

 lower part of its course; has steep banks; forms some rather deep 

 pools; and is, like Ballard Slough, extremely muddy. A dense 

 growth of trees lines its banks. It was continuous as far as fol- 

 lowed towards the Mississippi River (although greatly reduced 

 at some points), and, judging from the current, was doubtless 

 yet connected with the river. Still there can be no doubt that 

 it commonly dries up largely in summer. 



