THE WONDERS OF LIFE 



out of inorganic compounds under the influence of light. 

 The water that is needed for this, besides nitrogenous 

 compounds (nitric acid, ammonia), is drawn from the 

 earth by the roots; the carbonic acid is taken from the 

 atmosphere by the green leaves. The immediate prod- 

 ucts of the synthesis, due to the separation of the 

 carbonic acid, is, as a rule, a non-nitrogenous starch-flour 

 (amylum). This is further used for the composition 

 of the nitrogenous albumin by an as yet unknown 

 synthetic process, with the aid of nitrogenous mineral 

 compounds. In this process of reduction the separated 

 free oxygen is returned to the atmosphere. The carbo- 

 hydrates that chiefly co-operate in this are glucoses 

 and maltoses : the mineral substances, especially salts of 

 potassium and magnesium, and compounds of these 

 elements with nitric acid, sulphuric acid, and phosphoric 

 acid. Iron is also found to be an important element in 

 the process, though in a very small quantity. As a rule, 

 the ferruginous chlorophyll can only form new plasm 

 with the help of light-waves. The most important part 

 of the spectrum for this fjurpose is that containing the 

 red, orange, and yellow waves. 



The chief factor in plasma-formation in the organic 

 world is the photo -synthesis, or ordinary carbon- 

 assimilation by chlorophyll, the wonderful green matter 

 that amounts to only a very small percentage (about one- 

 tenth) of the weight of the chlorophyll-granules, and can 

 be separated from their plasmatic substance by certain 

 methods. Even when the plant has some other color 

 than green the chlorophyll is still the real plasmodomous 

 substance. Its green color is then masked by some 

 other color — diatomin in the yellow diatomes, phy- 

 corhodin in the red rhodophyceae, phycophaein in the 

 brown phasophyceae, and phyocyan in the blue-green 

 chromacea or cyanophyceae. The latter have an especial 

 interest for us, because in the simplest specimens the 



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