74 MASSACHUSETTS HORTICULTtRAL SOCIETY. 



3. Temperature of the inclosed air. 4. Anesthetic used. Phints 

 treated in October require a longer period of treatment and a larger 

 amount of anesthetic per cubic foot of air space than similar plants 

 treated in November. The same statement applies equally as well 

 to November and December treatments. Briefly stated, the later 

 the treatment the shorter the period of exposure, and the smaller 

 the amount of anesthetic used. 



Johannsen (15) says "The influence of the ether upon the plant 

 varies greatly with the temperature. The higher the temperature 

 the stronger its influence. An amount of ether which has no effect 

 at a temperature of 32 degrees F. will injure the plant very seriously 

 at a temperature of 86 degrees F." Generally it is best to let the 

 ether act upon the plant forty-eight hours ; at the end of the resting 

 period, however, twenty-four to thirty-six hours may be sufficient. 

 At the beginning of the late resting stage or in the early resting 

 stage seventy-two hours may be necessary for lilacs." 



Very good results may be obtained from repeated etherization; 

 first forty-eight hours then ventilation of the chamber for a similar 

 period, afterward a second etherization in the same manner as the 

 first. A dose of ether may vary from 5-15 c. e. per cubic foot of 

 air space enclosed. Usually from 10-15 c. c. are employed. Occa- 

 sionally a larger dose may be used. Maumen^ (19) recommends 

 the following amounts of ether per cubic foot of air space: 



Lilacs 13.7-15.7 c.c. 



Azalea mollis 13.7-15.7 c. c. 



Virburnum opulus 14.8-16.4 c. c. 



Prunus persica 1 



" triloba [ 11 .7-13.7 c. c. 



" sinensis J 



Spiraeas (varieties) 12.5-14.8 c. c. 



Deutzia gracilis 13.7-15.7 c. c. 



Lilies and 



T •, p , T7 11 r 13.7-15.7 c. c. 



Lily-of-the-Valley 



Our experience with lily-of-the-valley leads us to recommend 

 not over 10 c. c. of ether per cubic foot of air space. Better results 

 have been secured with this amount than with larger doses. 



Doses of other anesthetics as employed at the Vermont Experi- 

 ment Station are as follows: 



