208 



Journal of Agricultural Research voi. xvni, isio. 4 



Table XIII. — Analyses of sugar solutions of increasing concentration inoculated with 



spores of Aspergillus niger 



Treatment. 



10 per cent solution, uninoculated . . 

 10 per cent solution, inoculated with 



spores at 100° C 



10 per cent solution, inoculated with 



spores at 63 ° C 



20 per cent solution, uninoculated . . 

 20 per cent solution, inoculated with 



spores at 63° C 



30 per cent solution, uninoculated. . 

 30 per cent solution , inoculated with 



spores at 63° C 



40 per cent solution , uninoculated . . 

 40 per cent solution, inoculated with 



sporesat 63° C 



50 per cent solution, uninoculated . . 

 50 per cent solution , inoculated with 



spores at 63° C 



60 per cent solution, uninoculated . . 

 60 per cent solution, inoculated with 



spores at 63 ° C 



70 per cent solution, uninoculated . . 

 70 per cent solution, inoculated with 



spores at 63° C 



After 2I4 days' incubation. 



Polari- 

 zation. 



24. 

 24. 

 22. 



47- 



72. 



71- 

 96. 



96. 

 120. 



120. 

 144. 



144. 

 168. 



168.0 



Decrease 

 in polari- 

 zation. 



Decrease 

 in sucrose. 



Per cent. 



0.27 

 •IS 



Reducing 



sugars. 



Per cent. 

 14 



14 



32 

 20 



29 



35 

 45 



45 

 56 



57 

 70 



73 

 80 



Increase in 

 reducing 

 sugars. 



Per cent. 



o. 18 



09 



It will be observed that inversion occurred to a slight extent in 10, 

 20, and 30 per cent concentrations but not beyond this point. This 

 corroborates the results previously obtained with the spores oi Aspergillus 

 sydowi and establishes the upper limit of concentration for the in- 

 vertase activity of these spores. When recalculated it is found to be 

 between 18 and 24 per cent actual sucrose in the solution. 



The query, therefore, which was considered as a basis for this in- 

 vestigation, Do mold spores contain enzyms? has been answered in the 

 affirmative by virtue of the evidence advanced. 



It is irrelevant at the present time to do more than indicate the sig- 

 nificance of the industrial applications of this biological principle. We 

 have already mentioned that it plays a considerable role in the deteriora- 

 tion of sugar by materially affecting the factor of safety rule. It may 

 likewise explain certain transformations in the soil which occur as a 

 result of mold activity where mycelia are not found in great abundance. 

 Thus the universal distribution of molds and their activities will un- 

 doubtedly suggest many further developments of this phenomenon, 

 some of which are at present under investigation in this laboratory. 



