28 
ACTIVE ALBUMEN 
The solution, in which we cultivated Spirogyra nitida and 
Sp. Weberi for the purpose of making the tannin disappear, 
contained : calcium-nitrate, magnesium-nitrate and potassium- 
sulphate, 0,05 per cent of each, monopotassium-phosphate 0,005 
per cent and a trace of chloride of iron. A few threads were 
placed in a liter of this solution, which was at a temperature 
of 15 —j 6° left, exposed to only a moderate amount of light for 
2—3 weeks. 
An object entirely free of tannin or related compounds are 
the snowberries (Symphoricarpus racemosus). If the fleshy tissue 
of unripe snowberries be treated first with coffeïn, and the pro- 
teosomes be left in diluted (0,1 per cent) ammonia, the tissue 
then washed with tepid water to remove every trace of sugar, we 
observe also here an intense blackening of the proteosomes by 
the silver reagent mentioned. 
The question, whether our labil proteosomes represent the 
active albumen of our theory is easily proven. If favorable con¬ 
ditions for growth and multiplication of cells were offered and at 
the same time the formation of new albumen was made im¬ 
possible, then the reserve-albumen had to be used up gradually. 
We shall indeed observe this result if we cultivate for instance 
threads of Spirogyra in a comparatively large volume of the 
following solution : 
0,05 per cent calcium sulfate, 
0,02 ,, ,, calcium bicarbonate, 
0,02 ,, ,, magnesium sulphate, 
0,005 »? 55 monopotassium phosphate, 
Small trace of chloride of iron. 
In this solution were present all the mineral constituents 
necessary for development, except every suitable source of 
nitrogen, hence new albumen could not be formed and the 
reserve albumen had to be seized upon for the organisation of 
growing protoplasm, for the nucleus and chlorophyll-bodies of 
the new cells. Indeed the stored-up albumen disappears here 
so perfectly, that coffeïn fails to produce proteosomes after 2-3 
1) Hereby the quantity of originally present active albumen is found relatively 
decreased in the cells, on account of their multiplication, but the proteosomes produced 
remain perfectly colorless, if the threads are left to die in a solution of ferrous 
sulphate ; a proof, that every trace of tannin was used up. 
