360 Reviews— Vogt on the Antiquity of Man. 
population retreated southward, as is shown by the shells found in the 
German Ocean and the Baltic. When the cold became less intense, 
it returned towards the north. Such physical changes, producing 
immigrations and emigrations, require much time : only a long series 
of centuries, the number of which can scarcely be estimated, could 
have been snfficient. He gives a minute description of the coal-beds 
of Eastern Switzerland, some of which Prof. Heer estimates to have 
required a period of 9,600 years for their deposition. ‘They contain 
freshwater snails of living species, the elytra of small marsh- 
beetles, and remains of Elephas antiquus and Rhinoceros leptorhinus. 
These coal-beds were formed upon the glacial clay immediately after 
the retreat of the glaciers; they were then covered by the alluvium : 
whence he draws. the consequence that the beds in which Elephas 
primigenius and Rhinoceros tichorhinus occur are somewhat later 
than the slate-coal beds. 
Greenland, a continent not less in extent than the whole Scan- 
dinavian peninsula, is covered with an ice-crust 1,000 feet thick, 
moving from the interior towards the west coast. It there breaks 
up to ‘form the icebergs which cover the Northern Atlantic, ulti- 
mately melt, and leave their freight on the bottom of the sea. He 
considers that the same occurred in Norway, Sweden, and Finland, 
where the sea gradually rose, the land became warmer, the ice- 
shroud melted, and the ice was left in the valleys, between the 
pinnacles of land that then showed themselves. The sea rose about — 
500 feet, as we find up to this height deposits of extinct Arctic 
mollusea. The melting ice produced large streams, which formed 
Jakes, and deposited the finer materials transported by them, as loam, 
marl, and sand-clay. Erratic blocks were brought down by the 
glaciers, and these were deposited on the banks. This theory is 
supported by the researches of Kjerulf, Sars, and Lovén; and ana- 
logous phenomena are exhibited in England, Switzerland, North 
America, and elsewhere. Prof. Vogt is led to the inference that 
the Diluvial period lasted an incalculably long time, during which 
there was much elevation and subsidence in land and sea, and many 
mutations of species of plants and animals. 
We copy the table on opposite page from Professor Vogt’s work. 
That Man appeared in our hemisphere only in the course of the 
Diluvial period, Prof. Vogt considers to be an admitted fact. 
Whether, however, he appeared before or after the last glacial 
extension on our continent, is still an open question. After careful 
examination, Prof. Vogt arrives at the opinion that the apparition 
of Man in Europe is posterior in date to that of the formation of the 
Boulder-clay. He is willing to accept a higher antiquity of Man, 
should his remains be hereafter found either under the glacial clay, 
or under undisturbed Tertiary beds. He approves strongly the cal- 
culations of Dr. Bennet Dowler, according to which the age of the 
delta of the Mississippi Valley is estimated at 57,500 years, and 
quotes the discovery of burnt brick and pottery at the foot of the 
statue of Rameses as a proof of the high antiquity of certain Nile 
deposits. English geologists, who have already had frequent oppor- 
