1921] 
WEBB—GERMINATION OF SPORES OF CERTAIN FUNGI 333 
The titration curves of the liquid culture media, fig. 1, show 
that “water HCl or KOH” has the least buffer action and that 
beet decoction has very little more. "These facts, then, would 
seem to offer an explanation of the expanded favorable range 
under conditions of active alkalinity, with such solutions on 
the basis of buffer effect or change in reaction of the medium 
during germination. In this connection, Itano and Neil (719) 
have recently shown that the spores of Bacillus subtilis germinate 
A 
* eo 
8 
e 4 2s°e ~ 
> E VA 
: — —— - J e j Nb sa y= — 
PN , ea 2 N 
"Ü > L Nom VT su TR 
Tq / == 
9 ~ 
v L4 
i: \ 
Py ff 2 3 4 " é 7 8 H / 
Fig. 36. Colletotrichum Gossypii in 2 per cent bacto-peptone solution. 
in a broth medium between Pg 5.0 and 10.0, and that few spores 
ordinarily germinate at the H-ion concentrations closely ap- 
proaching those of inhibition. Inafew days, however, the spores 
germinate and exhibit all characteristic phenomena, thus indicat- 
ing that by the life processes of the organism the reaction of the 
medium approaches that of the optimum. The final hydrogen- 
ion concentration of the medium, as determined from numerous 
other contributions for the bacteria, depend upon (1) the organism, 
(2) the composition of the medium, (3) the initial reaction, (4) 
the buffer effect, (5) the nature of the acid, (6) the period of 
incubation, and (7) other conditions favoring or hindering 
growth. It must be emphasized here that the Px values which 
appear in this paper always represent, unless otherwise specified, 
the initial reaction or hydrogen-ion concentration of the medium. 
The results of my experiments dealing with this phase of the 
problem do not seem to warrant an explanation entirely on the 
basis of change reaction of the medium during germination. 
The matter appears to be further complicated and obscured by 
