04 WIE JOON AE (OIF (GE OILOG V4, 
as its inherent character, preclude this belief. From the quan- 
titative standpoint also, the drift border is not always such as 
would have been produced by icebergs. The drift is often too 
thick along its border and that in situations where there could 
have been no shore, and therefore no exceptional accumulation 
of berg deposits to refer it to icebergs. Like other parts of the 
drift, the border is made up of materials which were largely 
gathered close at hand. The glacier ice itself, or some agent 
capable of accomplishing results which have not been dis- 
tinguished from those of glacier ice, reached the approximate, 
and often the exact southern border of the drift-covered area. 
Further, the character of the drift and its accompanying phe- 
nomena indicate that the same forces which were operative on 
the higher lands in the production of the drift, were operative on 
the lower also. There is not a higher body of drift of one sort, 
and a lower body of drift of another sort, as this hypothesis 
would demand. 
Nevertheless, nothing which is here said precludes the idea 
that lakes of lesser or greater magnitude may have been asso- 
ciated with the ice sheet for longer or shorter periods of time at 
one stage and another of its development. If such lakes existed, 
iceberg deposits were doubtless made in them. Berg deposits 
were doubtless likewise made wherever the glacier ice reached the 
sea, and since the coastal regions may have been lower than now, 
it is altogether possible that some of these berg deposits were 
made on areas which are nowland. The foregoing considerations 
seem only to preclude the attribution of any large part of the 
drift to bergs, or to floating and grounding ice. 
Glaciers and pan-ice.—Any conditions which would allow of 
the co-operation of glaciers and icebergs, would also allow of the 
co-operation of pan-ice. If the coastal regions were lower than 
now, while ice covered that part of the drift area which was not 
submerged, shore ice might have been operative over a narrow 
belt determined by the position of the shore line. Since the 
shore lines must have varied with varying altitudes of the 
land, ice-floe and other forms of shore-ice may have operated at 
