INJECTION EXl'KimiENrs OX Pr.\NTS. o 



spaces and the lumen of vascular bundles more easily than tlie 

 interior of the cells. 



The range attainable by the injected solution may differ in 

 accordance with the structure, size and nature of the plant, the 

 direction of the injecting needle applied, the intensity of the pres- 

 sure of injection, the amount of the solution injected, etc. I 

 found by my experiments that the injected solution, 0.03 c.cm. — 

 0.15 c.cm. in volume, does not extend far from the point of 

 injection, but is arrested within a few centimeters. 



III. Experiments with various injection solutions. 



The following aqueous solutions were used in my experi- 

 ments : — 



lOX. 



Lithium is a metal which is not usually found in the plant 

 body, but there are some plaats containing it normally (Tscher- 

 MAK 5), hence in experimenting with a lithium salt solution, we 

 must take care to choose a plant which is free from it. 



Lithium salts act poisonously on several plants (Gtauneesdoefer, 

 6) even in small quantities, but as its toxicity is not so intense 

 as that of SO^Cu or eosin, and moreover, as it is quickly carried 

 through the plant body, it may most suitably be used for our 

 purpose. A minute amount of lithium is readily detectable spec- 

 troscopically and we can roughly determine its amount from the 

 intensity and duration of the red lithion line (Teuchot, 7). Obser- 

 vation has shown that it is sometimes obscured by the presence 

 of too many other metal-lines appearing in the spectrum. 



