Vol.. 8, 1922 
BIOLOGY: A. P. DACHNOWSKI 
229 
which occurred nearly simultaneously over a large part of northern America 
and northern Europe. The combined evidence suggests that it is possible 
to date with fair exactness the general course of events since the last Ice-age. 
This chronology may furnish important data bearing on different branches 
of science. 
(a) The estimate on the duration of Post- Wisconsin glacial time in 
the United States is based chiefly on the recession of the waterfalls of the 
Niagara. The figures for the larger subdivisions fall within the estimates 
made by Reeds, Coleman,^ Taylor/ Chamberlain and Salisbury 2. 
TABLE IV 
Profuse Sections From Peat Deposit oe Europe 
XI XII XIII XIV XV XVI XVII 
8. 
7. 
6. 
GERMANY 
ENGLAND 
AUSTRIA ALPS 
SWEDEN 
SWEDEN 
RUSSIA 
RUSSIA 
Sphagnum 
Heath 
Sphagnum 
Top removed 
Sphagnum 
? 
Sphagnum 
Forest 
+ 
Sphagnum 
Shrub forest 
Sphagnum 
Sphagnum 
Forest shrub 
Sedge-Reed 
(Forest) 
+ 
Sphagnum 
? 
Sphagnum 
(Forest) 
+ 
Sphagnum 
Forest 
Sedge 
(Forest) 
+ 
Sphagnum 
Forest 
Sphagnum 
5. 
Sedge or 
Forest shrub 
Forest 
Forest 
Reed 
Forest shrub 
Forest 
Hypmum 
Reed 
Sedge 
4. 
Sedge 
+ 
Reed 
Reed or 
forest 
Macerated 
Sedge 
+ 
Reed 
Reed and 
drifted 
timber 
Hypnum 
Reed 
Reed 
Hypnum 
Macerated 
Macerated 
Sedge 
Macerated 
Macerated 
3. 
I" 
Macerated 
Macerated 
I. 
{h) The time units of measurement of Penck,^^ DeGeer,^ Wahnschaffe^^ 
and Brooks^ are more or less similar with the dates delimiting the American 
stages. 
4. The correlation of past climates in the United States with those of 
the European last glacial period has not been worked out on a meteoro- 
logical basis but there is sufficient information at hand of considerable 
interest for comparison with the conclusions based on European evidence. 
The results of the correlation agree in showing that, although the evo- 
lution of climate has been continuous, there have been several climatic 
waves since the last glacial period, each of relatively long duration. The 
climatic pulsation, resembling a climatic belt, consisted of a cold- and humid 
period bordering the glacial readvance, followed by a warmer, drier period 
