Pieters: Ferax Group of Saprolegnia 
311 
A second culture and count gave the following results : 
Culture 
No. 
Date 
Temperature 
No, Counted 
No. WITH 
Antheridia 
2iF 
Dec. 9, 1913 
Room temp. (22° -j- C.) 
Many 
0 
2IF 
«l 4« 
Cool (i2°-i5° C.) 
100 
15 
2IF 
“ 24, “ 
Room temp. 
80 
I (doubtful) 
25 
i * ** •• 
Cool 
100 
9 
25 
** •• *• 
** 
100 
12 
28 
" 18, “ 
“ 
100 
3 
28 
“ 24, “ 
** 
100 
3 
28 
** ** ** 
Room temp. 
60 
0 
33 
“ 18. “ 
Cool 
100 
2 
33 
** •• •* 
100 
6 
33 
“ 24. “ 
Room temp. 
100 
4 
34 
“ 18, “ 
Cool 
100 
2 
34 
“ 24. “ 
Room temp. 
100 
7 
34 
** •• •* 
100 
1 
35 
(4 44 
Cool 
100 
2 
35 
44 44 44 
100 
5 
35 
“ 13. “ 
Room temp. 
100 
19 
35 
“ 18. " 
Cool 
100 
7 
35 
44 44 44 
“ 
100 
7 
35 
" 24, “ 
Room temp. 
100 
5 
37 
18, “ 
Cool 
100 
I 
37 
44 44 44 
* * 
100 
9 
37 
“ 23, “ 
Room temp. 
300 
0 
The average number of oogonia accompanied by antheridia in 
cultures grown at a low temperature (about 12° to 15° C.) is 
shown in the following table : 
Culture Number 
2iF 
25 
28 
33 
34 
35 
37 
Average Percentage of Oogonia 
With Antheridia 
8 
8.8 
4 
4 
2 
8.4 
5 
In all the cultures cited above, the oogonia were substantially 
alike, of the same size and pitting, with slight fluctuating varia- 
tions. The vegetative parts and the sporangia were also alike, 
but all of these cultures differed strikingly from number 17 which 
I collected in Germany and number 82, collected at Ann Arbor 
and which proved to belong to the same species as 17. These two 
forms had a flaccid delicate mycelium just as de Bary described 
for S. mixta and as Kauffman noted in his culture “ H.” The 
pits on the oogonia, though present, were less prominent than on 
