I20 



BOTANICAL GAZETTE 



[PEBRUARY 



It Will be noticed even when magnesium greatly preponderates in 

 the mixed solutions the plants live twenty-five times as long as in pure 

 MgCl^, and over eight times as long as in pure KCl. Increasing the 

 proportion of potassium increases the length of life. 



The same relation is seen more completely in the next table (Table 

 V). Decreasing the amount of Mg causes increased growth up to a 

 certain point (loo K+io Mg). Still further decrease of the relative 

 amount of 'Mg beyond this point is imfavorable. The optimum 

 relation is therefore not far from lo ]Mg + loo K. 



TABLE V 



Liverworts 



Ail quantities given are cubic centimeters of .0375W solutions 



Culture solutiom 



Growth in 150 days: gemsiae 

 of luntjlaria 





KCI... 



ICO KCI 

 5 MgCl. 



100 KCl 

 10 MgCl. 



100 KCI 

 25 MgCI 



MgCU 



Distilled water 



Length of 

 thallus 

 in mm. 



0-5 



3 30 



3-4X 



2.6 



o-S 

 6.60 



Percentage of 



gain in length 



of thallus 



560 



582 



420 



I230 



It will be noticed also that the gemmae made no growth whatever 

 in pure MgCl^ or pure KCl^ while in mixtures of the tw^o a good growth 



ed. 



W L w ij-j 



wer 



For the study of flowering plants wheat was chosen. The seeds 

 e supported in the solutions on strips of filter paper as described 



m a previous paper.'* The results agree with those akeady given. 

 Table VI shows that certain mixtures of potassium chlorid and mag- 

 nesium chlorid are much more fa%-orable than either of the pure salts 

 (see also figs. 2, j). 



^OsTESHomr, Bor. G.\ZEXTE 44:259-272. 1907. 



