in the Bromes and their Brown Rust. 263 
TABLE V. 
Exp. No. 785. Readings of thermometers outside, and compared with ordinary readings on grass and in air. 
Date. 
Hour. 
Conditions. 
Black bulb 
thermometer. 
Ordinary 
suspended 
thermometer. 
Thermometer 
wrapped in 
grass-leaf. 
Thermometer 
lying in 
grass-tuft. 
Thermometer 
suspended 
horizontally 
above ground. 
July 28 
11.40 
a.m. 
Clouded over 
21*2° C 
21-2° C 
2 1° C 
20.6° C 
21*1° C 
33 
11.45 
„ 
Sun out 
M -5 
22-5 
23 
21 
24 
33 
11.50 
33 
Clouding 
22*5 
21.6 
21*8 
21-2 
22 
33 
n -53 
33 
33 
21 
21 
20-9 
20-5 
21-5 
33 
n -55 
33 
33 
20-6 
20-8 
20.5 
2O.4 
21-5 
33 
1 2 noon 
33 
20*6 
20-6 
20-6 
20-2 
21 
33 
12.15 
5J 
2O.5 
20-6 
20.5 
19.8 
20*8 
Too cloudy 
to continue 
July 29 
10.45 
a.m. 
Full sun 
25-5 
23 
24-5 
24 
23 
33 
10.55 
>5 
33 
25.8 
22-9 
24 
22* 
243 
33 
11. 15 
33 
26*1 
23*5 
23-5 
I9.5* 
19.9* 
33 
11.40 
33 
2 7 
24-1 
24 
23*5 
24-3 
33 
12.10 
noon 
33 
27.4 
24*6 
25-5 
24*5 
25 
33 
12.20 
5 > 
33 
29 
25-5 
26*2 
24.9 
26-6 
33 
12.30 
5 > 
33 
28.2 
25.4 
25.8 
26 
27-8 
33 
12.45 
JJ 
33 
28-2 
25 
25*9 
26 
27-5 
33 
1 
p.m. 
33 
29-1 
26 
26.4 
25.6 
28 
33 
1. 15 
” 
28 
25-9 
26 
25.2 
27 
* Shadow of a distant chimney. 
may be visible in half an hour or less, and the germ-pores may 
begin to swell even earlier. The spores float on the water- 
drop and are not easily wetted : they usually aggregate in 
films, in which it is observable that the spores are not in 
contact, but remain separated by what looks like a clear 
interval equal to about the diameter of the spore. 
The germ-tubes grow very rapidly, attaining lengths equal 
to from twice to five times the diameter of the spore, in 
a couple of hours at 20° C. 
The germ-tube usually branches when it has reached a 
length equal to about five times the diameter of the spore, 
and quickly-growing tubes put out a large number of very 
short branches along the sides, giving them a curious knotted 
appearance, a peculiarity already remarked as being charac- 
teristic for this species, and figured by Eriksson (loc. cit, 
plate X, Fig. 115). 
It is astonishing how little seems to have been done in 
