Influence of Certain Carbohydrates on Green Plants 15 



of 350 cubic centimeters capacity. As a substratum for growth, cotton, 

 pumice, or sand was employed. To this was added the nutrient solution 

 to be tested. The results, summarized in the following table, clearly 

 indicate that radish can absorb and assimilate the organic acids, such as 

 malic, tartaric, succinic, and citric, and their salts, and comparison is made 

 with glucose: 



General Averages of Results Obtained for the Differ::]nt Groups of Substances 



Culture medium 



Free atmosphere 



Green 

 weight 

 (milli- 

 grams) 



Dry 

 weight 

 (milli- 

 grams) 



Relative 

 acidity 

 of plant 



Confined atmosphere 



Green 

 weight 

 (milli- 

 grams) 



Dry 

 weight 

 (milli- 

 grams) 



Relative 

 acidity 

 of plant 



Knop (check) 



Knop 4- KHSO4 (acid salt) 



Knop -(- K2SO4 (neutral salt) . . . 



Knop -|- glucose 



Knop -|- free organic acids 



Knop -|- acid potassium salts of 



organic acids 



Knop -f- neutral potassiiun salts of 



organic acids 



749 

 811 

 793 

 1,035 

 945 



1,030 



947 



36.3 

 41.0 

 42.0 

 54.9 

 52.5 



53.9 



53.6 



1.0 

 1.1 

 1.0 

 1.3 

 1.5 



1.4 



1.2 



166 

 250 



247 

 306 

 426 



515 



466 



11.7 

 16.9 

 17.0 

 30.5 

 30.5 



33.3 



28.7 



1.5 

 1.5 



1.4 

 1.8 

 2.2 



1.9 



1.7 



Palladine (1901), Palladine and Komleff (1902), and Maige and 

 Nicolas (1910), have studied particularly the influence of various organic 

 substances on the rate of respiration. Their investigations will be con- 

 sidered subsequently in this paper. 



Not only do the phanerogams have the ability to absorb organic 

 substances, but the same property has been shown by algae, as has been 

 demonstrated by Bokorny (1911), Ravin (1913), and others. Recently 

 Servettaz (1913) has investigated the absorption and assimilation of 

 organic substances by mosses. He finds that glucose and fructose are 

 readily utilized, whereas the disaccharides saccharose, lactose, and maltose 

 ate of less value and are absorbed in the order given. Dextrin, starch, 

 and gum arable seem to be detrimental to moss plants. Peptone also is 

 utilized. The observation was made that the moss in the presence of sugar 



