Fritsch and Haines .— The Moisture-relations 
,706 
upon which stress has already been laid, appears very indicative of a capacity 
on the part of these terrestrial forms to accommodate their cells to extreme 
conditions of their environment. 
The possibility of the xylol present in the sealing medium being 
responsible for the results recorded in this section was disproved by placing 
two mats of Zygogonium respectively in 5 per cent, sea-salt solution and 
a similar solution to which a small amount of 5 per cent, sea-salt, previously 
shaken up with xylol, had been added. The dishes containing the solutions 
were covered over with glass plates and estimations of the two sets of 
material were made two days later in the usual way. The results were : 
Solution. 
5 % sea-salt 
Ditto + xylol 
It is seen that the effect of the xylol is in the opposite direction to that 
noted in the above experiments, and its presence cannot therefore be respon¬ 
sible for the observed results. 
The frequent recovery of the cells of the terrestrial forms studied from 
plasmolysis in hypertonic solutions led us to attempt their cultivation in 
such solutions. With this end in view, small patches of soil bearing mats 
of Zygogonium , Hormidium , and protonema were placed in wide crystal¬ 
lizing dishes in solutions of sea-salt of various strengths (usually 5 per cent.), 
partly out of doors and partly in a warm greenhouse; the dishes were 
covered with glass plates and exposed to varied illumination. Except in one 
experiment with Zygogonium in a 5 per cent, solution, however, no further 
growth of any of the forms was noticed. In the one case small tufts of 
threads arose from the edge of the mat and trailed out into the surrounding 
fluid. Such growth was, however, limited to a fortnight, and some weeks 
later a large number of the constituent cells proved to be dead, whilst others 
(nearly always granular cells) were perfectly healthy and green, though 
mostly plasmolysed. 
The general result of the remaining experiments of this kind may be 
briefly summarized as follows. A large number of the cells of the three 
forms examined remain in a healthy condition for periods of six weeks to 
three months and upwards, the duration of resistance probably depending 
inter alia on the condition of the original material. Those of the cells that 
suffer from the conditions of the experiment die in a relatively short space 
of time, probably usually within the first week, and show brown, often un¬ 
contracted contents. The surviving cells are very commonly the granular 
ones, and in the case of protonema, where the mortality is much greater, 
especially those situated at the tips of the branches. A variable number of 
the surviving cells are found to be plasmolysed, and this is often the condi- 
Cells 
counted. 
Strongly 
plasmolysed. 
0/ 
Slightly 
plasmolysed. 
°/ 
Unaffected. 
c / 
1,021 
966 
Vo 
22*9 
/o 
2 3’4 
Vo 
53*7 
3 X *5 
37-4 
31*0 
