SPECIMENS OF LYGINODENDRON OLDHAMIUM. 353 
summer weather it cut like very stiff cheese, but in the cold winter months 
it was necessary to warm it over a stove to prevent it from shattering when 
cut. By means of a pantagraph, in which the pencil was replaced by a sharp- 
pointed stylo, the outlines obtained by tracing were enlarged to two diameters 
directly on to the wax. These outlines were cut out and carefully numbered. 
The model was then built up by comparing one slide with the next, arranging 
Fia. 4. 
Ground-plan of Dr. Scott's specimen ; constructed from the model. 
'The main axis bears five leaves, of which three subtend branches, "Two of the 
branches show further ramification. 
the pieces of wax in their appropriate positions with regard to one another 
and to the previous sections. When absolutely in place the edges were melted 
together. A good deal of trouble was experienced at this stage because the 
wax kept breaking apart at unexpected places between the sections. When 
complete, hot copper wires were thrust in to bind the whole together and 
to give it stability. In modelling Dr. Scott's specimen this difficulty was 
