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 — t6° left exposed to only a moderate amount of light for 

 2 — 3 weeks. 1 * 



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 coffein, 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 » >' 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 coffein 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. 



