SYMPOSIUM ON COLLOIDS 



57 



(plasmahaut?) to salts of the alkali metals and many other 

 substances (20, 21), thus probably reducing - the toxicity of 

 these substances to the organism. This effect has been de- 

 scribed under the term antagonism. Recognizing- Cranner's 

 contribution, wall as well as the plasmahaut effects may be in- 

 volved in antagonism 1 . It is also not proved that an- 

 tagonism results alone from permeability change. It may in- 

 clude adsorption phenomena (2: p. 60; 21) or something quite 

 different, such as induced or stimulus effects rather than direct 

 physical changes. 



We might summarise what we have said on the relation of 

 various substances (ions and molecules, especially of salts, 

 acids, bases and anesthetics) upon colloids of the living cell. 

 In certain concentrations and mixtures they maintain the con- 

 sistence and other physical characters of cell colloids neces- 

 sary for the proper functioning of the organism. Hober and 

 others emphasize in this connection the colloids of the plasma- 

 haut and believe that the effect of these substances upon the 

 irritability, permeability (35), etc., of the organism can 

 largely be explained through their effects upon this organ 

 (1 :pp. — ). Cranner (19) would emphasise in addition their 

 importance in maintaining the proper consistency of the cell 

 walls in plants; while Martin Fischer sees no less significance 

 in their effects upon all colloids of the organism, including sols 

 as well as gels. 



Besides the general nutrient function of salts in plants, such 

 as the use of nitrates, phosphates, sulphates and magnesium 

 for the synthesis of proteins, nucleoproteins, lecithin, chloro- 

 phyll, etc., all salts or rather all ions of salts have effect on 

 the physical characters of the colloids of the organism. The 

 necessity of calcium for most plants can best be explained to- 

 day by its function in maintaining the proper consistency of 

 the colloids of the organism wall and protoplasm. We have 

 much yet to learn concerning calcium in this regard and even 

 more concerning potassium, magnesium and other ions 3 . 



There is evidence that some very important morphogenic 

 or development changes are brought about by changes in the 

 amount of water held by cell colloids at the time particular pro- 

 cesses are occurring in the organism. Certain work indicates 



1. Indeed it is not established that the plasmahaut alone determines the entrance 

 of materials into the cell. Other layers of the protoplasm may be involved and in 

 plants the permeability characters of walls and change of these with conditions 

 should not be neglected. This is especially emphasized by recent study of many 

 walls in seed coats showing peculiar osmotic characters in part at least resembling 

 those of the plasmahaut. 



2. This is not denying still other functions of salts in plants. 



