(lateral Physiology of Plants 



197 



Fig. 57. Details of equipment used in studying the basipetal 

 secretion of water by excised tomato roots, showing the glass mano- 

 meters, rubber hose, and metal clamps at various stages in their 

 assembly. (From White, P. B. 1938. Am. J. Bot. 25 : 225, fig. 5, 

 267.) 



