124 SOME RECENT RESEARCHES IN PLANT PHYSIOLOGY 



Within the triangle the point M, for example, denotes 

 a molecular concentration of 25 per cent. CaCl 2 , as it is 

 on the line FJ parallel to the base which is opposite the 

 CaCl 2 apex, and begins and ends at points which are distant 

 from the base 25 per cent, of the length of a side, and 

 situated in the sides BA and CA. The point M is also on 

 the lines EH and GL denoting concentrations of 50 per 

 cent, potassium chloride and 25 per cent, sodium chloride 



FIG. 9. SOLID MODEL SHOWING THE FORMS OF THE ANTAGONISM CURVES 

 IN ALL POSSIBLE MIXTURES OF NACL 0'12 M, KCL O13 M., AND 

 CACL 2 0-164 M. 



respectively. Accordingly M represents a mixture of 

 25 per cent, calcium chloride, 50 per cent, potassium 

 chloride, and 25 per cent, sodium chloride. 



At any point on or within this triangle ordinates may 

 be erected to denote the growth of the plant organ under 

 investigation. When a sufficient number of points have 

 been obtained, a solid model may be constructed. This 

 describes completely the amount of growth taking place 

 in any of the solutions. Fig. 9 shows such a model. In 

 the solid figure the additive effect is represented, not by a 



