546 Holmstrim—‘ Vestiges of the Ice-Period,’ 
polished on the surface, and scratched or furrowed by some violent 
external agency. In order to explain this phenomenon and those 
connected with it, he supposed that a flood or deluge (“rullstens flod,” 
literally ‘‘flood of the rolled stones”) had overwhelmed all Scandina- 
via, passing from North to South, carrying along with it great 
quantities of stones and gravel, and that the subjacent mountains had 
been ground and furrowed in the direction of the current, ‘just as a 
polished slab of marble is furrowed by sand grains that are pressed 
in a continuous straight direction on its surface.’ 
After having examined the vestiges of the glacial epoch, Dr. Torell 
embodied the results he had arrived at in an academical treatise, 
published in 1858 (‘ The Mollusk-fauna of Spitzsbergen’), and there 
described the facts which, in his opinion, prove that all Scandinavia 
was once covered by snow and ice. During the progress of these 
researches he was led to results which had not been expected when 
the above paper was written; and he could not find anything support- 
ing them in previous papers. He did not then suppose that the ice 
which had covered the mainland of Scandinavia had stretched farther 
than the coasts and the nearest adjacent islands. He tried to explain 
this by the fact that, during the Glacial epoch, the land was higher 
than it now is, and the islands close to the shores must then have ~ 
been united with the mainland. 
It has been known, since the beginning of this century, that a 
large part of Northern Europe is, as it were, overstrewn with ‘er- 
ratic blocks,’ the origin of which all naturalists agreed to seek in 
Scandinavia. The general opinion then was, that these stones had 
been carried from Scandinavia on ice-floes, and then deposited on 
the bottom of the extensive sea supposed to have stretched from the 
White Sea to the German Ocean. 
In a paper which Dr. Torell communicated last year to the Royal 
Academy of Sciences in Stockholm, he endeavoured to show that the 
hypothesis of such an ocean was contradictory to facts, and that the 
transport of the blocks resulted from the large continental ice-cover- 
ing of Scandinavia having spread over all the region where the er- 
ratic blocks are found. He showed how the known fact, that the 
blocks from various parts of Scandinavia have a different distribu- 
tion beyond that region, could only be explained by the theory of 
their transport on a coherent and uninterruptedly progressing ice- 
field. A necessary supposition in support of this explanation was, 
that Denmark during this period must have been united with Scan- 
dinavia, and the author tried to prove that supposition. Continued 
researches made it apparent that several minor epochs or divisions 
could be discerned in the great Glacial period :— 
1. There are no facts which enable us to trace the extent of 
Scandinavian land-ice before it reached its greatest distribution. 
This extension may even now be determined by the boundary-line 
of the erratic blocks, and the period of its existence may be consi- 
dered the first part of the Glacial period. 
2. In the second epoch the mass of the ice was considerably di- 
minished. The Russian Waldai heights were no longer transgressed, 
