48 TRANSACTIONS—PERTHSHIRE SOCIETY OF NATURAL SCIENCE. 
the events which make up that history. Although we stop here, 
however, we need not fancy that, because the work seems finished 
around us, all is now at rest. On the contrary, the work is still going 
on, and the history is literally “a story without an end,” for the vitality 
of the world itself is the outcome of constant modification and 
incessant change. 
The following local (diagrammatic) Sections will, it is hoped, 
help the elucidation of the foregoing paper :— 
C _ _ 
r — — — _ 
Section I.—Across Valley of Tay near Guay. 
a—a are the boulder clay resting upon the primeval rocks ; h — -h, immediately 
post-glacial “accumulative” river material, which was built up to much higher 
levels, as indicated by the broken lines c, ; d—d are “dispersive” river beds, 
which were left more or less fragmentary upon the successive valley floors of the 
denudation during the period of the “ great upheaval ” and down to present times. 
