Sandsten: influenxe of gases and vapors upon growth. 65 



growing. In dissecting the bulbs the floral structures were 

 found to be very much dwarfed but the bud scales were well de- 

 veloped. The scapes or flower stems were greatly reduced, 

 being only from 5 to 18 mm. in length. The bulbs which were 

 treated with i/iooo part alcohol showed the same dwarfed con- 

 dition of the floral organs. 



Bulbs of AriscB7na triphyllum, Crocus and Tulip were treated 

 with the various reagents, but no satisfactory result was ob- 

 tained. All the Croats bulbs died from some unknown cause 

 or causes. The Ariscema bulbs were undoubtedly affected by 

 the change in temperature which occurred on the morning of 

 November 23, and to which reference has previously been made. 



5. The Influence of Gases upon Growth of Plants 

 Grown in Nutrient Solution of Water Culture. 



A. Land -plants grorvn in nutrient solution. Seedlings of 

 Zca inais were used in these experiments and the method de- 

 scribed in the introduction was observed. The duration of the 

 experiment was limited to eighteen days. The average growth 

 for this period, taken in four separate experiments in which the 

 seedlings were grown in a nutrient solution saturated with com- 

 mercial nitrous oxide, was 203 mm. for the roots and 209 for 

 the shoots. The control plants grown in nutrient solution with- 

 out nitrous oxide showed an average growth of 213 mm. for 

 the roots and 165 mm. for the shoots. The result shows a gain 

 in favor of the nitrous oxide in the shoot and a loss for the root, 

 but the result needs verification. 



B. Aquatic -plants grozun in river water. Wide bell jars 

 were inverted and filled with about one inch of soil over which 

 a thin layer of clean sand was spread ; in this substratum several 

 plants of Philotria were planted and the bell jar filled about 

 half full of river water. The water in the bell jars was kept 

 saturated with nitrous oxide by means of inverted bottles which 

 were first filled and inserted under water and this water was dis- 

 placed by nitrous oxide. The bottles were kept in position by 

 means of iron stands. The bottles were refilled as soon as the 

 gas was exhausted. 



