238 
The Ohio Naturalist. 
[Vol. VIII, No. 3, 
Reticulation. The two eskers show several connecting 
branches. This implies a union between the lines of drainage 
some time during their existence. These connecting branches 
are so depressed in parts that tracing is difficult. Such a condi¬ 
tion would be natural as the cross drainage would normally be 
so sluggish that the tunnel carrying it would probably never 
attain a large size. It is a question whether the two eskers repre¬ 
sent branches from one line of drainage or are entirely indepen¬ 
dent. They may even represent a shifting of drainage lines. 
The lower end of No. 1 suggests by its position (Fig. 1) that it 
may be a branch from No. 2, rather than a continuation from the 
head end of No. 1, as we have described it. 
Fig. 4 (F. Carney). Camera reversed from fig. 3, and view taken 
looking south on same esker. 
Knolls. Hummocks are frequent. Generally they mark the 
southern termini and ridge junctions. At its head end No. 2 is 
composed of a series of four joined together. Many theories 20 
are given for the origin of such swellings. In connection with 
knolls other modifications of the esker type may be noted. 
Several buttress-like deposits were found lying against the bases 
of the eskers; sometimes also a fan-like spreading of debris from 
a similar position was observed. These irregularities probablv 
mark the entrance to the major line of small tributary streams, 
or as an alternative, the opposite condition, leakage from the 
major lines. The knolls at the head of No. 2 are more sugges¬ 
tive of tributaries than of kames. 
The knoll-endings (Figs. 1, 6) on the Miami Valley suggest by 
their alignment that they have been cut off at this point by the 
Miami River. Though this stream here turns to the westward, 
the even floor of the valley is evidence that it formerly turned 
20. J. B. Woodworth, loc. cit., pp. 202, 203. 
