Balls. — Temperature and Growth. 581 
cultures, on account of the greater bulk and concentration of the latter, as 
will be seen below. 
The effects of boiling a stale medium are rather erratic. It would seem 
that the decomposition of ‘ # ’ is more rapid in dilute solution, in thin 
films, and in small bulk of medium. These facts indicate that it is not an 
enzyme, and that its disappearance is due rather to chemical change than 
to physical displacement. 
In no case was the stopping-point lowered by boiling the stale medium, 
although some thirty experiments were made> either directly, or in con- 
nexion with some other object. The application of heat to the medium 
either produced no effect, or else caused growth to cease at a higher 
temperature than had previously been the case . 1 
Decomposition of t x\ Curve 4, 
Nearly stale culture medium. Not diluted. Boiled for four hours under reflux 
condenser, followed next day by two hours’ boiling in the steam sterilizer. 
Tube inoculated evening of 22/4/07, at 22°C. 
Set up 10.15 a.m., 23/4/07. Galvanometer zero, 30 cm. 
Readings of micrometer eye-piece scale in length-units of -003 mm. (columns 2, 
3 > 4 , 5 )- 
! 
2 
3 
4 
5 
6 
7 
8 
Time . 
Control 
Point . 
End of 
Hypha . 
Length 
under 
observa - 
tion . 
Growth per 
Minute {by 
difference ). 
Temperature 
of Bath . 
Readhig of 
Galvano - 
meter . 
Notes . 
10 46 p.m. 
1 
39 -o 
38.0 
•7 
26-7 
43 
1 
•7 
•7 
•6 
33 
44 
1 
4°-3 
39*3 
•8 
26-7 
30*5 
49 
o -3 
40.4 
40*1 
26-7 
28 
50 
5 1 
10.52 p.m. 
•0 
45-5 
42-5 
— 
2S.5 
27 
53 
2.0 
45-5 
43-5 
1,0 
— 
— 
54 
— 
— 
— 
— 
30-3 
3 i -5 
55 
20.0 
47 
27 
— 
— 
— 
5 6 
i8-o 
46 
28 
1,0 
33-6 
46.5 
57 
— 
46-8 
28.8 
.8 
— 
4 T, 5 
58 
— 
48-0 
30-0 
1-2 
33-5 
37 
59 
19-0 
49.0 
30.0 
0-0 
— 
33 
11.0 
I 5 *° 
45 *° 
30-0 
— 
— 
28.5 
A rapidly growing hypha, branching from the one previously under observation. 
11. 1 p.m. 
12 
36 
24 
— . 
— 
— 
2 
14 
38 
24 
0-0 
35 *° 
31*5 
3 
18 
42 
24 
— 
34-9 
27 
4 
19 
43 
