General Physiology of Plants 



207 



Fig. (52. Detail of a mass of meristematic cells from the outer 

 region of a culture of undifferentiated callus from a plant of the 

 hybrid, Nicotiana langsdorffi x N. glauca. Delafield 's haematoxylin- 

 safranin. x 1000. (From White, P. R. 1939. Am. J. Bot. 26: 

 63, fig. 11, 78.) 



