232 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
ought to expect the escarpment to increase in height as one goes 
northeast, since in this direction the distance from the Gulf increases 
while the distance from the Atlantic remains fairly constant. To the 
southwest the escarpment should decrease in height until a point 
equidistant from both Gulf and Atlantic drainage is reached, when 
the two peneplains should merge and the escarpment disappear. 
This agrees fairly well with the facts as noted above, the Blue Ridge 
escarpment increasing in height as one goes northeast from the Tallu¬ 
lah district until it reaches its maximum in North Carolina and Vir¬ 
ginia; whereas it decreases to the southwest to a point near Atlanta, 
Georgia, where it seems to disappear entirely. 
(4) The Tallulah and other mountain groups. — These constitute 
outliers of the Appalachian mountains, and as already noted are 
residual masses left unreduced by the erosion which formed the sur¬ 
rounding peneplain. They rise distinctly above the Chattahoochee 
level, and come so far eastward north of the Tallulah River that the 
level referred to is much obscured or wholly undeveloped in portions 
of that region. Having no critical bearing on the problem of river 
capture, they may be dismissed without further discussion. 
(5) Streams of the Chattahoochee dramage.-^-The main tributary 
to the Chattahoochee system in the Tallulah district is Deep Creek. 
The name is curiously inappropriate, since many other creeks in the 
region are located in deep gorges, while this one and its tributaries 
flow in fairly open valleys on the upland surface of the Chattahoochee 
level. I followed along this creek from near its source west of Tur- 
nerville, to its junction with the Soque River, and was impressed with 
the maturity of its development, the absence of falls or rapids through¬ 
out most of its course, the open character of its valley, and the rela¬ 
tively sluggish water. One of its tributaries, Glade Creek, was like¬ 
wise traversed from its source to its mouth, and even this small branch 
showed a degree of maturity in striking contrast with other streams 
close by, to be described later. 
(6) Streams of the Lower Tugaloo drainage. — That portion of the 
Tugaloo River which flows over the lower level east of the Chattooga 
escarpment has a fairly open valley, as have also its main tributaries. 
Where these streams are actively cutting headward into the higher level 
and pushing back the escarpment, narrow valleys and extensive falls 
are common. Even as far east as near Toccoa a splendid fall is 
encountered on a branch of Toccoa Creek. 
