THE ETHERIZATION OF PLANTS. 75 



The best temperature at which to treat the plants is in the neigh- 

 borhood of 60 degrees F. It may vary however between 55 and 65 

 degrees F. without materially influencing the results. If higher 

 temperatures prevail the dosage, period of treatment, or both 

 should be reduced accordingly. 



Experimental Evidence of Growth Acceleration Due to 

 Anesthetics. 



The experimental e^•idence now at hand regarding the relative 

 increase in earliness of blooming period as a result of anesthesia 

 shows that the time element varies inversely to the earliness or 

 lateness of the forcing period. It has been clearly shown by care- 

 fully conducted experiments that anesthetics impart a more decided 

 growth impulse in the early and after rest period than in the central 

 or toward the close of the dormant season. On the average one 

 may expect, in such plants as lilacs, that those etherized will come 

 into bloom from 8-10 days earlier than the untreated ones. This 

 period of difference is frequently very greatly exceeded. Harris (11) 

 claims to have secured a ten days gain with lilac Charles X, and 

 in addition the etherized plant produced about three times the usual 

 number of flowers. It was also noticed that the foliage was much 

 more abundant and of a deeper green. 



Lewis (18) reports very satisfactory results from etherized nar- 

 cissus, gains of from 2-21 days being secured. Howitt (13) found 

 that etherized Astilbe Japonica came into bloom a month to five 

 weeks earlier than untreated plants. 



* Ethyl chloride may be used in the ordinary way or it may be used as a spray. 

 On account of its very low boiling point it is a difficult substance to handle and 

 its use is not advised. 



