196 



I'huit Tissue Culture 



Fig. ."><;. A manometer attached to a single excised root growing 

 in its culture ll;isk. Water is secreted into the manometer, forcing 

 the colored index drop upward iii the capillary. (From White, P. 

 K. L938. Am. J. Bot. 25: 224, fig. 2, ?67.) 



