[Vou 11 
76 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
they are 3.4 and 6.9 and 3.4 and 7.0. Only at 15? C. is there 
any indication of a pronounced optimum Pg, this being 5.6 with 
82 mgs. of growth. At the 2 higher temperatures the optimum 
growth-zone is Py 4.9-6.5, while at 15? C. it is somewhat nar- 
rower, being 4.3-6.0. 
Richards' sol. 
TABLE XI 
THE GROWTH OF VIA EUM COMMUNE AND THE CHANGES IN THE 
ACTIVE ACIDITY UPON BOTH THE RICHARDS' AND THE PEPTONE 
SOLUTIONS AT vH INITIAL Рн AND TEMPERATURES 
15° C. 25? C. 35? C. 
Рн Wt. of Рн Wt. of Pu Wt. of 
mat in mat in mat in 
Initial | Final mgs. Initial | Final mgs. Initial | Final | mgs. 
3.4 3.4 0 3.4 3.4 0 
3.7 3.7 0 3.9 3.6 30 3.9 8-7 22 
4.3 3.7 52 4.2 3.6 82 4.3 3.8 26 
5.0 3.8 47 4.9 3.7 35 4.9 3.8 33 
5.6 4.5 82 5.4 3.8 42 5.4 4.6 37 
6.0 5.4 54 5.9 4.6 36 5.8 5.1 30 
6.5 6.4 18 6.3 5.6 37 6.3 5.5 45 
6.6 6.4 35 6.5 5.8 38 
7.0 7.0 0 6.9 6.9 0 7.0 7.0 0 
2.8 2.8 0 2.8 2.8 0 2.9 2.9 0 
3.5 3.5 trace 3.5 3.6 3.5 3.5 97 
3.9 4.7 687 4.0 5.8 569 4.0 5.8 327 
| 46 5.7 844 4.4 6.0 645 4.4 6.1 483 
S| 5.0 | 5.9 884 4.9 6.0 671 5.0 5.8 388 
o 5.5 5.9 880 5.4 6.0 645 5.3 5.9 391 
8| 6.0 | 5.8 866 5.6 | 6.0 742 5.6 | 5.9 | 289 
> 6.0 | 5.8 560 6.0 | 6.3 512 
£| 6.6 5.9 553 6.4 5.9 542 6.7 6.4 465 
7.0 5.9 431 6.9 5.9 550 7.0 6.4 400 
7.6 | 6.3 391 I3 i 511 7.5 | 6.5 | 305 
8.0 6.5 196 8.0 8.0 0 
8.5 8.5 0 8.5 8.5 0 
In the peptone solution (fig. 16) the fungus again shows opti- 
mum growth at 15° C. with a range from Ру 2.8 to 8.5. This 
is а narrower range on the acid side than that for either 25? C. 
or 35" C. but a wider range on the alkaline side than for 35? С.) 
the intermediate temperature having a range from Pa 2.8-8.5 
and the higher from 2.9 to 8.0. Тһе optimum Ру zone at 15? C. 
is 4.6-6.0 with a maximum of 884 mgs. at Pa 5.0, and at 25° С. 
it is 4.4-5.6 with a maximum of 742 mgs. at Pa 5.6. At 35° C. 2 
the growth curve fluctuates widely through a range of 200 mgs. | 
between Ри 4.4 and 7.5, making it difficult to show either an 
