ii8 



BOTANICAL GAZETTE 



[FEBRUARY 



(MgCla and KClJ in proper proportions. In the mixture loo^^ MgCl^ 

 +40^*^ KCl, the plants were alive and in good condition at the end of 

 twenty days, when the experiment was discontinued. It is evident 

 therefore that ia the mixture of magnesium and potassium chlorids 

 the plants live five times as long as in pure magnesium chlorid and 

 three times as long as in pure potassium chlorid. 



TABLE I 

 Marine Algae 



All quantities given are cubic centimeters of 0.375OT solutions 



Culture solution 



Duration of life in 



days: ErUero- __ 



morpha Hopkirkit 



KCl. ..... 



100 KCl 

 40 MgCl. 

 MgCl. 



Distilled water. ... 



Sea water (total salts = 2.7 per cent.) 

 Artificial sea water (total salts = 

 2 . 7 per cent. : 

 roo NaCi 



y.SMgCia 

 3-8MgSO^ 

 2 . 2 KCl 

 I CaCU 



7 



20 + 



4 



20 + 

 20 + 



20 + 



The plus sign indicates that the plants were alive at the end of the expciiment. 



■V 



L 



The results obtained from the study of Vaucheria were < 

 striking. Zoospores were allowed to attach themselves 

 These were then rinsed in distilled water and placed in the 



The results are shown in thp fnllriwino- taW^ nnrl rt}^r, in £0 



T.\ELE II 

 Fresh-wateb. Alg.ab 



AH quantities given are cubic centimetei^ of .01m solutions 



CCLTURE SOLUTION 



KCl 



100 KCl 

 40 ]V%C1, 



MgClj.... 



water 



-2 



Development poring 45 DAira 

 Vaucheria terrestris 



Length of 

 thalias 

 in mm. 



Percentage of 

 increase 

 in length 



■^ 



6.45 



10. o 



4200 



o 



6k66.66 



