DAMPI^G-OFF IK FOREST Krt T RSERIES. 5 
saprophytes that one of them might easily get into a killed seedling 
after some other parasite had caused its death. Not only in the 
case of seedlings killed by fungi like Peronospora parasitica, but in 
HOST 
YEHR 
EXPT. 
\IOO 
P/AfCAS 
STffOBUS 
PVA^6/<S &/9HH>S/<9A//? 
P/HU<S . 
POHO£/?OS# 
PINU8 PES/A/OS4 
IQ/3 
/9/<3 
19/4- 
/9/4 
1917 
/9/B 
28 P 
28 B 31 
36 4-7 
45 
7/ 
72 
- 
K x 
" 
/■ \ ■ 
i/ \ y\ 
/ 
1 -y-...\ 
\ S \ * 
* r \ 4* 
" ^*^«* 
V * A 
"^ \ V\ 
\ /\ \ 
■ * \ 
\ \ 
\ V 
i 
i 
it 
J 
// 
/ / 
/ 
~^H 
— i 
l 1 1 1 
! 
' » 
Fig. 1. — Diagram showing the relative activity of different strains of Corticium vagum 
in inoculations made at the time of sowing the seed. In experiments Nos. 36, 45, and 
47 the values are plotted for the number of seedlings appearing above the soil. For the 
other experiments the number of seedlings surviving at the close of the experiment have 
been taken. Explanation of symbols : = Strain 147, from spruce seedlings, Washington, 
D. C, 1910; +=strain 50, from pine seedlings, Nebraska, 1909; □ =strain 233, from 
Elaeagnus sp., Kansas, 1913; ■ =strain 230, from the same lesion as strain 233; 
$ =strain 183, from bean, New York, 1910. 
HOST 
P/A/C/8 
S7POBUS 
/=>//V<AS B/9A/HS/RA/# 
P/MOS 
POHOEROSP 
P/NUS RES/HOSff 
YEAR 
/9I3 
/e/i3 
19/4 
IB/4- 
/PAS 
19/ 7 
EXPT, 
23 
1 
\I20 
§ 
*.90 
28/9 
23 B 
<3I 
5/ 
4-9 
72 
7/ 
3v 
y*> 
/ \ 
/ \ 
— — "■ ""^V * 
A 
V CL» _^r^ 
% 60 
1 
1 ° 
\ 
•J / . 
if 
X 
***«Q 
Fig. 2. — Diagram showing the relative activity of different strains of Corticium vagum, 
as indicated by the number of seedlings surviving in inoculated soil. Explanation of 
symbols: ©=Strain 1S9, from sugar beet, Michigan, 1910 (light-brown mycelium with 
few sclerotia) ; A=strain 211 and A=strain 212, from sugar beet, Colorado, 1910; 
■=strain 186, from potato, Ohio, 1910 ; D=strain 187, from potato, New York, 1910 ; 
+=strain 205, from Douglas fir, Colorado, 1911; X=strain 192 and 0=strain 206, 
from pine, Nebraska, 1911. 
cases of true damping-off produced by the rotting type of parasite, 
much of the rapid decay of the seedling after death is brought 
about by bacteria and fungi other than the one causing death. 
