A NEW TRANSFER METHOD FOR 
STUDYING FOSSIL PLANTS 
BY 
William C. Darrah 
The microscopic study of fossil plants has made 
many great advances since Henry Witham published his 
histological investigation of several fossils from Great 
Britain in 1833. His study comprised notes on twelve 
species prepared by the thin section method, by which 
translucent sections could be ground from slices sawn 
from petrified specimens. This method has been in gen¬ 
eral use for more than a century. 
More recently translucent sections have been prepared 
by the peel method. A specimen is etched with a suit¬ 
able acid in order to dissolve the inorganic matrix and 
expose the carbonized portions of the preserved plant 
structures. Following this step, a solution of nitrocellu¬ 
lose in butyl acetate is poured over the etched surface. 
After the nitrocellulose has dried it can be peeled off, 
pulling with it a nearly perfect replica of the preserved 
structure. 
The thin section can be subjected to magnifications 
from 100 to 250 times, but the thickness of the glass slide, 
the thin section of the fossil, and the cover glass collec¬ 
tively prevent the use of higher magnifications—at least 
with transmitted light. A ground section is almost al¬ 
ways more than one cell thick. 
The nitrocellulose peel, in contrast, may be so pre¬ 
pared that the thickness of fossil is from one to three 
micra, frequently much less than one cell in thickness. 
However, the thickness of the nitrocellulose is relatively 
great. Even so, magnifications greater than 500 times are 
usually permitted, and occasionally excellent photo¬ 
graphs can be made at magnifications of 1200 times. 
[35] 
