694 Fritsch and Haines .— The Moisture-relations 
and under the heading of ‘slightly plasmolysed ’ cells in the final drought 
condition there are therefore comprised a more or less considerable percent¬ 
age of cells which are in this permanently contracted state. Probably, 
therefore, a considerably larger percentage of cells than is shown in the 
alternate lines of Table V is to be regarded as unaffected by the plasmo- 
lysing solution. In the case of the protonema, which otherwise falls into 
line with the filamentous algae, the great apparent increase in slightly 
plasmolysed cells seems due to a relatively larger number of the cells 
being in this permanently contracted state than in the algae investi¬ 
gated. 
Table VI. 
Successive estimations of material of Zygogonium (>habitat II) exposed 
to drought over 34-5 per cent . sulphuric acid. 
(Experiment XVI, 5 % sea-salt.) 
Date. 
Cells 
counted. 
Strongly 
plasmolysed. 
O/ 
Slightly 
plasmolysed. 
0/ 
Unaffected. 
0/ 
Dead 1 
cells. 
0/ 
April 1 2 
1,226 
/o 
71-8 
/o 
167 
/o 
11 ‘5 
/o 
16*3 
» 2 
9 : 3 
49‘5 
41*0 
9*5 
15*0 
}y 3 
860 
30-8 
45*6 
23.6 
18*3 
»> 4 
900 
13-8 
3 2 *3 
53*9 
247 
0 5 
823 
6*6 
25-6 
67-8 
347 
„ 6 
841 
o -5 
I 5 * 1 
84*4 
207 
Material at this stage of drought transferred to damp 
air (cf. p. 708). 
„ 7 
57 i 
0*2 
14-4 
85*4 
28*0 
„ 8 
398 
0-3 
i6*i 
83.6 
25-6 
» 19 
1,042 
I-I 
51.2 
47*7 
35*3 
„ 28 
518 
0-2 
48.2 
5 i *5 
3 i *9 
May 3 
495 
o*8 
59*6 
396 
27 9 
„ 10 
520 
i *7 
7°‘9 
27-3 
29.9 
„ 10 
264 
37*5 
53-8 
8.7 
— 
(10 % sol.) 
In most of the drought experiments repeated estimations were made 
during the period of desiccation—daily in the case of the short-period 
experiments. The progressive effects of drought could thus be studied, 
but the results are too numerous to be reproduced in full here. In illustra¬ 
tion we give one table (VI) and a number of figures (1-5). When the 
estimations are made at daily intervals, and provided a large percentage of 
the cells is strongly plasmolysed in the original material, one observes, in 
the case of the filamentous algae, for one or two days a more or less 
considerable increase in the number of slightly plasmolysed cells (cf. 
1 Where given, the dead cells are stated as a percentage calculated on the total number 
of living cells, instead of on the total number of cells, so that the percentages of plasmolysed cells 
recorded should represent a percentage of the living cells, i. e. of those still having the capacity to 
plasmolyse. 
2 The first line gives the condition of the material on the day of collection. 
