IE) 
sudden changes of the algae, as regards the sensitiveness 
to salts, when I worked in the light. If a new culture had 
to be used however, then it was necessary always to 
repeat the latest series of experiments, which were done 
with the old culture, with the new culture, to see whether 
the results with the new culture succeeded to those with 
the old culture. In most cases the difference was so slight, 
that the new culture can be used 
" ï Ï to continue the statements, 
without an interruption in the 
curve. In some cases however 
the new culture gave greatly 
deviating values. This case is 
made more clear by the curve, 
for potassium chloride (4, pag. 
| 56). With 0,00065 normal po- 
tassium hydroxyde. I did expe- 
riments with a new culture. 
The organisms of this culture 
appeared to be less susceptible 
to KCI than those of the old 
culture. The critical concen- 
tration was removed from 0,10 
normal to 0,14 normal. Probably 
the removal has not only taken 
place horizontally, but also 
vertically. Ï think that a part of the new piece of the 
curve corresponds to the last part of the old curve. The 
corresponding pieces were connected by dotted lines. 
Examples of less important removals gives the curve for 
mixtures of acetate and acetic acid (fig. 2). In this case 
algae from three different cultures were used. The critical 
concentrations obtained with organisms from each culture 
were mutually connected. Thus were formed the curves I, 
IT and III. 
Eiqele 
