66 



MINNESOTA BOTANICAL STUDIES. 



Table VII. 



I. Philotria in a saturated solution of N^O. 

 II. Control. 



The marked results shown in the above table were duplicated 

 in all the experiments set up. The average growth of the 

 Philotria branches after 28 days taken in another test from 

 four experiments was 17 mm. and the average growth from 

 the control was 11. 5 mm.; showing conclusively that nitrous 

 oxide has a stimulating effect on Philotria. 



To test further the effect of nitrous oxide on aquatic plants, 

 stems of Salvinia natans, having an aggregate of 80 leaves 

 were placed in bell jars set up in the same manner as in the pre- 

 vious experiment and the water kept saturated with gas. The 

 experiments were allowed to run for 40 days, when the number 

 of leaves were counted. The control or checks were set up 

 in exactly the same manner as the tests with the exception of 

 nitrous oxide. 



Table VIII. 



I. Salvinia in a saturated solution of N^O. 

 II. Control. 



The result of every experiment showed that growth was 

 accelerated by nitrous oxide. 



