Fig. 1. Junction between two acinar cells of guinea pig pancreas, cnij and cnig 

 =^ cell membranes of two adjacent cells; y = vesiculation of one cell mem- 

 brane ; er = endoplasmic reticulum. 

 Magnification = 38,333. (Palade and Siekevitz, IQodb. Reproduced by per- 

 mission of the Editors, J. biophijs. biochem. Cytol.) 



[facing page 18 



