7 02 
Fritsch and Haines .— The Moisture-relations 
It may be that the sudden drop in the number of slightly plasmolysed cells, 
which is to be observed in the filamentous forms after the experiment has 
been going on for some days, marks the death-point of a large number of 
the cells. 
The rapidity of recovery would seem to depend to some extent on the 
temperature. In Experiment XX with Zygogonium the second estimation 
carried out on a sealed slide kept in a warm room shows a much higher 
total of unaffected cells in the final condition than in any of the other 
similar experiments made with this alga. The experiment with Prasiola 
Fig. 7. Recovery from plasmolysis in a sealed slide. The heavy lines show the results 
for Zygogonhtm (Expt. XVI), the thin lines those for moss protonema (Expt. XV). 
was also conducted in May, whilst the others were performed in March or 
April. 
It has already been indicated that in Pleurococais , if recovery occurs at 
all, it usually sets in only after some days. In Experiment VII, however, 
some results were obtained which seem to indicate that, when the material 
is in a suitable condition, some at least of the cells may recover very rapidly. 
These results are set out in Table X and were all obtained on the same 
day with the same mass of material. They are so uniform, without any 
exception, that they can scarcely be due to experimental error, yet on other 
occasions (e. g. in Experiment XVII) nothing of the kind was to be observed. 
It is, however, to be noted that in the latter case there was no recovery even 
after seven days (cf. Table IX), whereas in Experiment VII recovery was 
evidently continued. 
