PLATE 52 



Fig. 1. Portion of dorsal cortex near the groove in the pedicel of \icot nnm, 

 showing the abscission process well under way. 



Fig. 2. Group of isolated cells washed off from end of a freshly abscissed 

 pedicel of Nicotiana. 



Fig. 3. Single isolated cell showing the thinness of the remaining cell 

 membrane. 



42(5 ] 



