Sandsten: influence ok gases and vapors upon (;ro\vtii. 55 



2 per cent, solution excited rapid irregular movements which 

 stopped inside of two minutes. Vacuolization followed rapidly 

 and the cell was killed inside of ten minutes. 



In the experiments where seeds and seedlings were used, Zca 

 inat'Sf Vicia and Phascoliis were employed exclusively. Straw- 

 berry plants of the common cultivated kind were used in the ex- 

 periments with growing shoot and proved w^ell adapted to the 

 work. The strawberry plants were taken from the bed on No- 

 vember 6, 1897, and carefully selected with reference to vigor 

 and equality. Two lots of plants were selected, one lot com- 

 posed of plants one season old, the other composed of plants two 

 seasons old. The plants were placed in three- and four-inch 

 pots respectively November 9th, and set in a cold frame where 

 they remained until December 9th, when they were taken to the 

 green house and put under the experimental conditions described 

 below. 



Dormant bulbs and corms of Arisceoiia^ Narcissus, Hyacinth, 

 Tulip, Frccsia and Crocus were used for material in the resting 

 stage. 



In the experiments with gases in nutrient solution in water 

 culture seedlings of Zca mais were used. A large number of 

 seeds were germinated in clean saw-dust and when the seedlings 

 had attained the desired growth the specimens which were to 

 be used in the experiment were carefully selected for vigor and 

 equality. The vessels holding the nutrient solution were glazed 

 earthen jars of two litres capacity. The tops of the earthen jars 

 were fitted with covers made of plaster of paris. Through each 

 cover two holes were drilled, one for the seedlings and a second 

 to admit the necks of inverted flasks of gas. The seedlings 

 were fastened in the openings in the covers by means of a per- 

 forated cork after the usual manner in water cultures. The 

 flasks were filled with water, inverted with the necks immersed 

 in the culture fluid and filled with gas by displacement through 

 a bent glass delivery tube. 



The following formula was used in making up the nutrient 

 solutions : 



Potassium nitrate 25. gm. 



Sodium chloride 12.5 " 



Calcium sulphate 12.5 "• 



Magnesium sulphate 12.5 " 



Calcium phosphate 12.5 " 



Water 250. cc. 



