I30 



BOTANICAL GAZETTE 



[FEBRUARY 



1 2 3 



23 



Time in hours 



Fig. 8. — Oxidation of pyrocatechin by first and second fractions of healthy bark, 

 with gelatine (for explanation of lettering see legend for fig. 7). 



12 3 16 40 



Fig. 9. — Oxidation of pyrocatechin by first and second fractions from diseased 

 bark, without gelatine (for explanation of lettering see legend for fig. 7); points of 

 plotting marked by vertical broken lines. 



Fig. 10.^ — Oxidation of pyrocatechin by first and second fractions from diseased 

 bark, with gelatine (for explanation of lettering see legend for fig. 7); points of plotting 

 as in fig. g. 



