704 Fritsch and Haines.—The Moisture-relations 
solutions; here again, as in the protonema, a slight increase in plasmolysis 
was often observed at first, to be followed by a subsequent slight decrease. 
These results bring out very clearly the great capacity for recovery on the 
part of the two terrestrial algae studied, by contrast with the moss (proto¬ 
nema and leaf), aquatic algae, and the flowering plant (see also Table XI). 
Table XI. 
Behaviour of the protoplasts of various forms when exposed to prolonged 
action of the plasmolysing solution in a sealed slide. 
(The figures give the areas of the protoplasts in percentages of the total areas of the cells.) 
Material. 
Strength 
Time in days. 
_ K - 
of sol. 
( 
I 2 
0 
5 
4 
5 
7 
Zygogonium 
Zo 
5 
82-2 88-3 
100*0 
— 
— 
— 
(granular) 
5 
9OI 100*0 
— 
— 
— 
— 
10 
82*2 82*4 
87*5 
95*8 
— 
— 
10 
72*0 93-6 
IOO-O 
100*0 
— 
— 
5 % NaC 1 
85*1 85*3 
98*6 
99*6 
— 
— 
Zygogonium 
5 
57 -° 78*5 
94*5 
— 
— 
97-3 
(non-granular) 
IO 
52-2 70-1 
50*8 
6o*8 
— 
— 
IO 
45*9 602 
96*8 
100*0 
— 
— 
Hormidium 
5 
85-2 87*9 
99.2 
— 
— 
100*0 
5 
81*7 — 
81*9 
90*9 
94 *i 
— 
10 
82*2 ioo-o 
100*0 
100*0 
— 
— 
10 
76-0 85-5 
8o*i 
8i*8 
— 
— 
5 %NaCl 
81-4 92-8 
94‘3 
87*7 
— 
— 
Protonema 
5 
75-8 — 
100*0 
80*2 
85-3 
— 
5 
7 T *7 ~ 
65*2 
66*3 
— 
— 
5 % NaCl 
83-0 80*4 
82*9 
85-2 
— 
— 
Spirogyra 
5 
887 — 
9°*5 
92*1 
93*7 
— 
(narrow sp.) 
5 
47-9 — 
100*0 
100*0 
100*0 
— 
10 
66-i ioo-o 
100*0 
100.0 
— 
— 
10 
9 I *3 7 2 ‘3 
43*5 
43’5 
— 
— 
Spirogyra 
10 
96*6 92*7 
92.3 
92*8 
— 
— 
(broad sp.) 
5 % NaCl 
67*5 36*6 
55*5 
64 7 
1 
The data given 
in the preceding 
paragraph 
were in 
part 
obtained 
merely by daily observation, but in a considerable number of cases more 
accurate means were employed in order to follow the stages in recovery. 
The method most usually employed, and that by which the results given in 
Table XI were obtained, consisted in making camera lucida drawings of the 
outlines of the protoplasts of selected cells on successive days and estimating 
the degree of contraction by finding the areas of the protoplasts as repre¬ 
sented in the drawings with the help of a planimeter. In Table XI these 
results are expressed as percentages of the total area of the interior of the 
cell as seen on the same drawings. Whereas the results epitomized in 
Table IX and Fig. 7 indicate the aggregate behaviour of the cells of a given 
mass of material, those in Table XI indicate the behaviour of individual cells. 
The most striking feature in the latter case is again the usually very rapid 
