582 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1959 
ings in plane and section form the solid basis on which all later work 
is built. 
SAMPLING METHODS 
The possibilities of carrying out investigations in the field without 
the use of instruments and chemicals are limited. Therefore, it is 
important to take samples for later investigation in the laboratory. 
These consist of samples for pollen analysis; samples for investigation 
of seeds, fruits, and shells; and samples for radiocarbon dating. 
Ficure 5 (left).—Small-leaved linden (Tilia cordata Mill.). 
Ficure 6 (right).—Oak (Quercus robur L.). (Drawings by A. Noll Sgrensen.) 
The pollen samples are taken in small vials which are pressed into 
the properly cleaned peat wall. The vertical distance between the 
samples is usually 2.5 cm.; in special cases they are taken at still 
smaller intervals. The pollen grains being microscopic, it is very 
important that the samples be pure; ie., that they are not contami- 
nated with peat from the layers above or below. After the sample 
has been taken, the vial is carefully corked and later sealed with 
paraffin so as to avoid contamination. 
In order to investigate the content of seeds and fruits, small sticks 
and twigs, and remains of insects or shells in the peat layers, larger 
samples are taken, usually about 200 cm. This is done by cutting a 
peat column out of the section. The column usually is 10 cm. broad 
and 10 cm. thick, and is cut into slices 2 cm, thick. Each slice is 
