PHYSIOLOGICAL BEHAVIOUR OF MALEIC & FUMARIC ACIDS. 485 



I. Experiments with Leaves. 



Young leaves were placed on the surface of 1 % solutions of 

 the neutral sodium salts of both acids and at the same time in 

 common water for control. 



Leaves of 



In maleic 

 acid. 



In fumaric 

 acid. 



In water. 



Brassica campestris 



Killed after 4 days. 

 „ 3 „ 



Killed after 6 days 

 „ 5 



Alive. 



II. Experiments with Whole Plants. 



Barley plants were placed in 2°/o solutions of the sodium 

 salts ; after 20 hours they were found to be killed by the sodium 

 maleate but were still quite normal in the fumarate, just as in the 

 control case with water. 



III. Experiments with Branches. 



Small young branches 10-15 cm. long bearing leaf-buds, or 

 flower-buds or both, were placed in 1 °/o solutions of the neutral 

 sodium salts and at the same time in common water for control. 



Branches of 



In maleic 

 acid. 



In fumaric 

 acid. 



Control. 



Oenanthe stolonifera 



Killed after 4 days. 



Killed after 10 days. 



Alive. 



Acanlhopanax spinosvm. . . . 



„ 7 „ 



„ 9 » 





Brassica campestris 



» 3 » 



„ 7 „ 





Evonymus Thumb ergianus 



„ 5 



„ 7 » 





Primus pseudoccrasiis var. 

 spontanea hearing 12 

 buds. 



Killed after 2 days, 

 no bud bad open- 

 ed at all. 



After 1 day 10 buds 

 had opened, and 

 on the 3rd day 2 

 more buds ; on 

 the 4th day how- 

 ever they died. 



All buds opened, 

 and remained 

 alive. 



Frtmus tnurnt bearing 5 

 flower buds. 



No buds opened, 

 after 3 days the 

 ends of the buds 

 turned brown and 

 died. 



After 1 day one bud 

 opened, but after 

 4 days all were 

 killed. 



After 2 days all 

 the buds had 

 opened. 



