MISSOURI AGR. EXP. STA. RESEARCH BULLETIN NO. 21 



a distinct shock to the cell protoplasm and tissue and acts as a sol- 

 vent in softening up the winter protecting scales inclosing the leaf 

 and flower buds." 



Johannsen 1 and Overton 2 showed clearly that desiccation cannot 

 be caused by the mild doses of ether which are effective in breaking 

 the rest period. Additional experimental evidence in support of 

 this fact is given on page 37 of this bulletin. Johannsen 3 believed 

 that etherization might either affect the vegetative activity, or it 

 might unfavorably influence the obstacles or inhibiting factors of 

 growth. He explained that small amounts of ether were apt to favor 

 vegetative activity, while larger doses, such as are given when the 

 rest period is to be broken, weaken or devitalize those factors which 

 are inhibiting growth, thereby indirectly favoring growth. 



According to Drude, Nauman and Ledien 4 ether and chloro- 

 form affect plants by checking some of the changes within the plant 

 cell, while at the same time increasing respiration. Muller-Thurgau 5 

 demonstrated that potatoes kept at a low temperature become 

 richer in sugar. Beltz 6 is of the opinion that ether and chloroform 

 bring about an enlargement of the cell similar to that occurring in 

 springtime. Molisch 7 pointed out that the warm bath method of 

 treatment affects plants by reason of the high temperature, the inhi- 

 bition of respiration under water, prolonged contact with water and 

 inbibition of water into the plant, thus facilitating the diosmosis of 

 substances in the cells and tissues. Iraklionow 8 believed that thru 

 the influence of the warm water bath the resting mechanism of 

 growth is set in motion thru the removal of a "catch." As a result 

 of this release, proferments are brought into an active condition. 

 These liberated enzymes then function as a lubricant which hastens 

 the reactions necessary for life. Kleb 9 held that during the rest 

 period there is an accumulation of organic foods which have been 

 assimilated after length growth has been suspended, but while the 

 leaves are still active. He says: " From this viewpoint we can argue 



1. Johannsen, W., Das Aethervergfahren beim Friihtreiben, etc. 



2. Overton, See reference to Johannsen, p. 58. 



3. Johannsen, W., Das Aetherverfahren, etc. p. 49. 



4. Drude, O., Nauman, A., and Ledien, F., Gartenbau Versuchein Dresden 

 1902-03. Jahresber. VII der "Flora" zu Dresden. 



5. Muller-Thurgau, JH. Landw. Jahresberich. Bd. 14. 



6. Beltz, W. J. The Effects of Etherization on Plants. Exp. Sta. Rec. 

 16, p. 978. 



7. Molisch, H. Forcing Plants by Warm Baths. Sci. Amer. Sup. 66 

 (1908) Exp. Sta. Rec. 20, p. 640. 



8. Iraklionow, P. P. Ueber den Einfluss des Warmbads auf die Atmung 

 u. Keimung der ruheden Pflanzen. Jahr. f. wiss. Bot. 51, pp. 515-540. 



9. Klebs, G. Ueber die Rhythmic in der Entwickelung der Pflanzen. 

 Bot. Centlb. 119 (1912) p. 426. 



