344 
Not much need be said about the tributaries of the Wabash, for Ley- 
erett has very fully discussed them. The details have not been worked out, 
and what is known was that most easily determined. Usually it is the 
lower portions of these streams and the lower portions of their tributaries 
that are well known, the headwaters being usually post-glacial and the pre- 
glacial valleys covered with drift. 
The course of White river below the north line of Greene county, with 
slight exception, is so completely covered with drift that the course of the 
preglacial stream can not be ascertained. For a few miles below Martins- 
ville the present stream follows a preglacial valley. The river below Spen- 
cer flows for a few miles in a narrow, shallow channel among the hills and 
ridges, there being no definite preglacial drainage lines to control its course. 
It occupies a preglacial valley from the mouth of Raccoon creek down to 
Worthington, where it joins a wider valley two to two and one-half miles 
wide, which trends south. From this point to its mouth, the course of the 
stream is nearly coincident with a broad preglacial line. 
Bean Blossom creek, which Leverett has not included in his map of the 
preglacial drainage of Indiana, is undoubtedly preglacial. This is the con- 
clusion of Dr. E. R. Cummings and VY. If. Marsters, both of Indiana Uni- 
versity, who have worked in this region (69). 
The Patoka is very interesting on account of the fact that it is a 
composite of the headwaters of four different stream systems. For short 
distances it follows a preglacial channel and then it suddenly crosses rock 
surfaces which were formerly cols between the preglacial streams. The 
three upper stream systems emptied northward in preglacial time into the 
White river. During the advance of the Illinois ice-sheet the mouths of the 
stream were dammed, and lakes were formed. ‘The water in the upper or 
eastern lake flowed into the next west over some low sag in the divide and 
this into the third. Whether the lake drained south over a sag into the 
Ohio or drained westward to the Wabash through some sub-glacial channel 
is not settled, but Leverett inclines to the latter (64: 101-2). 
The Ohio river (65; 183) below Madison is thought to be preglacial 
through its entire course along southern Indiana, except probably for a 
short distance at Louisville. as J. Bryson (12) and C. FE. Siebenthal (91) 
have discovered. This is Leverett’s conclusion also, but he says further, 
“A course about as direct is found in a line leading west from Madison, 
Indiana, along the Muscatatuck, to the East White and White rivers and 
