J. W. S. Macfik 
by the organism before it proceeded to divide, some of the double 
forms being made up of individuals 6/r or 7 p, in length, and others 
of 9p or lOp. The two components of each double form were, however, 
always approximately the same size, Spirochaetes resulting from a 
recent transverse division might therefore measure anything from 
about 6p to lOp, and spirochaetes measuring 13p or 14p might already 
be in a pre-division stage. There would therefore be a length at about 
Lengths in microns. 
5 6 7 8 9 1011 1213141516171819 20 
14p to 15p which would include both well grown single forms and 
small pre-division forms, and I believe that it is to this over-lapping 
that the small subsidiary crest seen on the curve of lengths is due. 
Breadth. Some of the spirochaetes were clearly broader than others, 
but so slender were the organisms that it was impossible to measure 
them accurately. So far as it could be estimated the breadth appeared 
to be about 0-2p to 0-3 p. 
