[Vor. 8 
64 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
conditions under which amyloclastic action could be studied. 
Thus, a means was furnished for determining whether the amy- 
lase produced by organisms requiring different H-ion concentra- 
tions for growth would be similar. 
Whether the enzymes produced by one fungus or different 
fungi under widely divergent environmental conditions have 
similar properties might assist in explaining such problems in 
parasitism as host specialization and the establishment of strains, 
and in saprophytism, specialization as to habitat. 
SURVEY OF LITERATURE 
The influence of acids and alkalis upon the activities of various 
enzymes was early noticed by different investigators. Pasteur, 
in 1879, observed the effect of acidity upon the alcoholic fer- 
mentation of wines and beers. Probably the first careful work 
on the influence of small quantities of acids and alkalis upon 
amyloclastic action was done by Kjeldahl (79). He showed 
that small quantities of mineral and organic acids increased the 
saccharogenic activity of a malt extract, while large amounts 
caused retardation. 
A voluminous literature has been developed, since that time, 
upon this aspect of amyloclastic activity. The early work relat- 
ing to the influence of acids and alkalis is very conflicting, both 
acid and neutral conditions being given as producing optimum 
activity. Many of these inconsistencies have arisen from a 
lack of means for determining the exact concentration of H and 
OH ions in the solution used in the experiment, and thus the 
data are often difficult to interpret. For this reason, the results 
of the early investigators have been omitted from the following 
discussion. An adequate review of the more important litera- 
ture may be found in the articles by Sherman and his associates 
(15) and in the texts by Bayliss (’14), Euler (’12), and Green 
(99). 
The perfection of methods for measuring H ion concentration, 
as discussed by Sörensen (709) and Michaelis (14), has been 
a means of obtaining valuable data in regard to the effects of 
H ions upon enzyme action. The establishment of definite 
P, ranges for the indicators has cleared up many discrepancies. 
Thus, in the work of Maquenne and Roux (7060), the maximum 
