246 BOTANICAL GAZETTE [MARCH 
is cut. These cylindrical blocks can be made of any thickness, and 
by varying the size of the mold can be made of any diameter. To 
render the cutting of the paraffin more satisfactory, the mold can be 
placed at a temperature of 30-35° C., which will be sufficient to 
keep the paraffin in a pliable condition. Another method for 
securing these blocks which has given good satisfaction is to pour 
the hot water and paraffin into shallow pans, forming a layer of 
paraffin above the water of any desired depth, and then allowing it 
Fic. 2.—Seedlings in paraffin blocks suspended in water to show root development 
to solidify. From the circular layer thus secured, the desired 
blocks can be cut with various-sized cake cutters. 
The blocks of paraffin thus secured are then perforated in one 
of two ways. In the one the ordinary cork-borer is employed, 
using two of different diameters, making a perforation with the 
smaller through the entire block, and then with the larger borer 
through the upper portion of the block. In this way a perforation 
is secured with a small shelf upon which the germinating seedling 
can be placed. Equally satisfactory has proved the method of 
