Effect of Illuminating Gas. 



85 



gas rather than to the natural death of the flower. Here as well 

 as in all other experiments checks were kept. Fig. 4a shows a 

 flower before being corked in a 20-liter carboy; Fig. 46, the 

 same after being corked in a 20-liter carboy (containing air 

 only) for twenty-four hours; Fig. 4c, a flower before 

 being corked in a 20-liter carboy and Fig. 4d, the 



Fig. 3. — Result of treat- 

 ing a bud, just beginning 

 to show the petals, for 

 three days with 1 part of 

 ethylene in 1,000,000. 



Fig. 4. — a, a flower that has just opened; b, the same after being corked in a 20-liter flask 

 of air for 24 hours; c, a flower that has just opened; d, the same after being exposed 12 hours 

 to 1 part of illuminating gas in 40,000; e, result of treating a flower that just opened for 12 

 hours with 1 part of ethylene in 2.000,000. 



