2 12 The Ohio Naturalist. [Vol. XI, No. 1, 



much more time than post-glacial time. Second, they do not act 

 like the Big Darby and other streams in the neighborhood. As a 

 general thing a stream here swings from one side to the other and 

 undercuts the bluffs; but not so with this one. The third fact is, 

 that the present streams are out of harmony with the size of the 

 valley. These facts suggest that the present streams ma\' have 

 had little part in the formation of the valley, but are only the 

 result of the present local rainfall. Did this region then at some 

 previous period have a larger rainfall? And has the rainfall 

 become less and so reduced the size of the stream? In answer to 

 these questions it should be pointed out that other streams in the 

 vicinity should show the same phenomenon. No such lack of har- 

 mony in size is found in any of the nearby streams. Thus we are 

 forced to the conclusion that the valley was formed by other 

 means than that of the present streams or the same enlarged by 

 heavier precipitation. 



vSince the theory that the valley has been made by its present 

 occupants seems to be untenable another hypothesis is proposed 

 for its origin, namely, that it has been formed by the ice. At first 

 this explanation looked very plausible but when one recalls that 

 the surrounding cotmtry is a till plain from fifty to sixty feet 

 higher than the ^'alley floor one wonders why the ice in this par- 

 ticular course cut a deep channel and left the surrounding till 

 plain smooth. We are unable to give a satisfactory answer to 

 this question. Further, if the ice carved the valley it seems at 

 least probable that the Darby would have used the ready-made 

 channel. 



There are several points which seem to indicate that the valley 

 is really a stream valley even if the present streams did not pro- 

 duce it. These points may be summarized as follows: (1) The 

 valley floor is nearly level across from one side to the other as all 

 stream-made valleys are and not U-shaped like ice-made valleys. 

 ' (2) The valley slopes are well graded and rounded at the top into 

 the upland plain on either side which would not be the case in an 

 ice-made valley. (3) A more certain proof that it is a stream- 

 made valley is that its floor is composed of fine silt with no admix- 

 ture of rocks. If it were an ice-made valley the floor of the valley 

 would be of characteristic drift. Thus it appears that it is not 

 made by ice but by a stream and that the streams found in it at 

 present are not responsible for its formation. 



There is a small stream entering this valley near its northern 

 entrance to the Darby which possibly might have been responsible 

 for this valley. This stream comes in from the west and cuts 

 across the northern end of the valley and flows into the Darby 

 through the valley's entrance into the same. But investigation 

 shows that this stream is entirely too small to have been responsi- 

 ble for such a vallev. A stream to have cut this vallev must have 



