13G 
Sydney H, Vines. 
iight, a thick paste-board cylinder was plaeed over the bell-jar. In the 
experiments v\ ith coloured light, double-walled flasks were used, Ihe spnce 
between the walls being filled in the one case, with ammoniaeal solution 
of copper oxide, in the olher, with saturated solution of potassic bichromate. 
The experiments went on during the rnonlhs of May, June and July 
of the year 1877, and amounled to about forty. Front thetn I have 
selected the following in illustralion of the results oblained. 
It was necessary, in the first place, to ascertain what was the na¬ 
tural course of grovvth of the plant, when exposed to conditions, which 
were kept as far as possible constant. Previous observations had shewn 
(hat the hyphae completed their growth in front 24 to 30 hours, (hat is 
the extent of the »grand period« of their growth. The following table 
gives an account of the variatious of growth during a considerable por- 
tion ol a grand period. The fungus was kept in the dark during the 
whole time of observalion. 
The course of the grand period is ntade more evident when a curve 
is constructed. The divisious of the abscissa are hours, and two of those 
of the ordinates are equal to one division of the micronteter 1 . The course 
of the temperature is represenled also bj a curve, eaclt division of the 
ordinales representing half a degree centigrade. 
I 
Hourly 
growth. 
Tempera¬ 
ture. 
6—7 
a. m. 
2.30 
25 0 C. 
8 
V 
2.90 
24.5 
9 
3.10 
23.9 
10 
JJ 
3.20 
24.1 
11 
3.50 
23.9 
12 
— 
3.60 
24.2 
1 
p. m. 
3.70 
24.1 
2 
4.10 
24.3 
3 
3.90 
24.2 
4 
„ 
3.70 
24.0 
5 
3.80 
23.9 
6 
4.00 
23.5 
The observations evidently coinmenced after the hypha had attained 
a considerable rapidity of growth. The curve gradually ascends ünlil the 
maximum rapidity is attained eight hours after the comniencement of the 
observations, and growth continues for a time with nearly that rapidity. 
The variations which occur are to be principallv allributed Io the course 
of the grand period, and secondarily to slight changes in thö conditions 
to which the plant is exposed. Such irregularities of growth were ob- 
served by Sachs in the case of internodes (stossweise Aeuderungen . An 
i) 
A division of the micrometer = 
J 
7ö 
mm. 
