Breaking Rest Period of Plants 87 



der, with a diameter of about two feet and is made 

 in two sections, each about three feet in length. The 

 lower section is fitted with a bottom and at the top, 

 around the rim, with a groove which is filled with 

 fine sand. The rim of the upper section flares out^ 

 so as to accommodate a lid. The latter fits in tightly 

 by being forced down in the sand. The second sec- 

 tion of the cylinder is like the first, except that it 

 is bottomless. When treating a large number of 

 plants at one time, the second section is placed upon 

 the first, the lower end being forced into the sand. 

 The ether is poured in through an opening in the 

 lid, which may be tightly closed by means of a 

 screw cap. The amount of ether used is at the 

 rate of 40 grams to each 100 meters of space. The 

 lid is weighted with bricks to prevent its being 

 pushed off by the ether vapor. Treatments should 

 preferably be given in the afternoon, or where there 

 is no likelihood of changes of temperatures. The 

 results of the treatment are summarized by Howard 

 in Table 14 on following page. 



From Table 14, it is seen that with certain plants 

 etherization breaks the rest period and hastens 

 growth (fig. 13, a-f.) while with others the treatment 

 has the opposite effect. In his investigations How- 

 ard* further found that the rest period of a large 

 number of woody plants may be largely overcome by 

 ether treatment (fig. 14, a-b.). On the whole, how- 



♦Howard, W. L., Missouri Agr. Expt. Sta., Research Bui. i6: 

 3-27, 1915. 



