4IO 



BOTANICAL GAZETTE 



[may 



the length of immersion which the 2 forms can withstand and 

 recover to a seemingly normal condition. 



After 12 hours' immersion in water all the thin-leaved shoots 

 were killed; some of the succulent leaved shoots survived partly. 



TABLE III 

 Rate of diffusion of acid in terms of cc. N/20 koh per gm. fresh weight 



AT I7°C. 



TABLE IV 



TABLE V 



Swelling of leaves of Castilleja at 16° c. 



The reactions of the succulent leaves are seen to present the 

 general aspects of sections of joints of Opuntia discata grown at 

 Carmel and tested at 16° C. at Carmel, July 1918. Swellings of 

 dried slices are as follows: 



