in the Bromes and their Brown Rust. 285 
before, and bright sunlight reached the plants for several 
hours during the afternoon. On the whole, this seemed to 
shorten the incubation period and to enhance the number and 
rapidity of the infections. The plants were somewhat drawn, 
owing to the damp close atmosphere, but the pustules de- 
veloped were larger and more numerous than in the last series. 
From this Table XIV may be gathered confirmation of 
TABLE XIV. 
Exp. No. 708, June io, 1901. ‘Seed ’ sown June 3. Seedlings germinated in open 
under hand-glass, and infected when one week old, and just above ground 
(2-5 mm.). The infected plants kept in laboratory, under glass, in W. window. 
Plants damp and somewhat drawn. 
Species. 
Origin of 
spores. 
Results. 
Approximate 
No. infected. 
Incubation 
period. 
No. of leaves 
with pustules 
on 1 4 th day. 
Period of 
observation. 
B. mollis 
B. mollis 
+ 
20 
9 days 
16 
21 days 
99 
B. sterilis 
— 
20 
0 
99 
B. velutinus 
B. mollis 
+ 
20 
1 
99 
B. sterilis 
— 
20 
0 
9 9 
B. maximus 
B. mollis 
— 
20 
0 
99 
99 
B. sterilis 
— 
20 
0 
99 
B. sterilis 
B. mollis 
20 
0 
99 
99 
B. sterilis 
+ 
20 
8 „ 
1 9 
99 
B. madritensis 
B. mollis 
— 
20 
0 
99 
99 
B. sterilis 
+ 
20 
9 » 
16 
99 
B. erectus 
B. mollis 
_ 
IO 
0 
99 
99 
B. sterilis 
— 
IO 
0 
99 
B. commutatus 
B. mollis 
+ 
20 
12 „ 
5 
99 
99 
B. sterilis 
— 
20 
0 
99 
B. arvensis 
B. mollis 
+ 
IO 
9 „ 
8 
99 
99 
B. sterilis 
_ 
IO 
0 
99 
B. secalinus 
B. mollis 
+ 
8 
15 „ 
3 
99 
99 
B. sterilis 
_ 
8 
0 
99 
B. interruptus 
B. mollis 
+ 
20 
10 „ 
7 
99 
9 9 
B. sterilis 
_ 
20 
0 
99 
B. racemosus 
B. mollis 
+ 
10 
12 „ 
3 
99 
99 
B. sterilis 
— 
10 
0 
99 
the readiness with which spores from B. mollis infect that 
species and B. arvensis and B. velutinus ; B. secalinus and 
B. racemosus being also successfully attacked, as are, moreover, 
B. interruptus and B. commutatus , all closely allied species, be it 
noted. B. sterilis y B. madritensis , B. maximus, and B. erectus, 
on the other hand seem immune, as in previous cases. 
Here, too, spores from B. sterilis readily infected only that 
