I894.J 211 [Woodwoith. 
intervening ponds and swamps. The terminals of eskers present 
a wide range of association with glacial and preglacial formations. 
The northern end of eskers frequently rises from a bouldery, 
swampy field, where the drift is generally thin, amounting only 
to so much as came to rest upon the bottom upon the melting of 
the ice which immediately overlay the locality. In other cases 
an esker springs out from a kame-field, or begins at the down- 
stream end of a drumlin or other partial obstruction to glacial 
motion. We should expect to find eskers produced in subglacial 
channels sometimes taking their beginning near a pot-hole or site 
of a moulin in the ice-sheet, where the superglacial drainage 
became subglacial. 
The southern end of eskers has more definite associations than 
the northern end. Eskers tend to terminate in moraine terraces, 
sand-plains, or kame-plains ; hence the term "feeder esker," but 
it is probable that moraine terraces and sand-plains are fed by 
independent streams, since these deposits are well developed 
where no eskers are present. Eskers sometimes terminate 
abruptly, as if the deposit were made in a channel which had been 
closed by tensions in the ice. 
Lineal Relations of Eskers. 
The following-named types of channels which may arise in an 
ice-sheet, to each of which eskers have been ascribed by different 
writers, will make clearer the lineal relations of eskers. 
1. Superglacial. 2. Englacial, or ice-tunnel. 3. Subglacial. 
4. Ice-canon. 
The normal course of glacier-born water may be taken to be as 
follows : A stream begins upon the ice, as rain or sun-melted 
glacier ice, and forms a superglacial stream; lower down, the 
stream drops into a crevasse or well and gives rise to a moulin 
and possibly a pot-hole if it reaches the bottom of the glacier ; 
the stream may become engiacial, flowing in a tunnel, with here 
and there a roofless way. In the tunnel, its deposits will be 
limited in cross-section ; in the open-air portion, the beds may 
assume the form of lake deposits ; the stream may reach the 
frojit as an englacial stream, or may join the sul:)glacial drainage. 
Streams flowing in channels under the ice will reach the front 
and may build frontal detrital deposits. 
