412 S. SAWA. COFFEINE AND ANTIPYR1NN. 



. ( A 

 Antipyrin -j -p 



Length of principal shoot 

 at the beginning, 

 cm. 



Increase in length of all 

 shoots combined. 



absolute 

 cm. 



relative 



so 



26 0 

 21.5 



3o 

 3-5 



"•5 



16.3 



CoReine j p 



IO. O 



21-5 



0 



0.2 



0 



0.9 



Control | ^ 



38.8 

 40.5 



26.7 

 26.5 



68 8 

 65-4 



In the second experiment the amount of these bases was 

 reduced to 0.1% and 0.2$%. This time young celery plants 

 of about 15 cm. height served for the test. After about two 

 weeks some injurious action was observed, commencing with the 

 wilting of the rim of the leaves. 



The injurious effect of coffeine in this high dilution appears 

 very remarkable since the epidermis of the tea leaves is compara- 

 tively rich in it and nevertheless remains uninjured. The coffeine 

 is here probably shut up in the vacuole surrounded by a tonoplast 

 of such density that the cytoplasm and nuclei are sufficiently 

 protected against the intrusion of the coffeine. A stimulating 

 effect of some kind or other can only be expected in still higher 

 dilutions of coffeine and antipyrine. 



