72 



SUBCELLULAR PARTICLES 



Fig. 4. Ciuinea pig fed after a fast of 48 hours. Pancreas fixed i hour after beginninj; of Jiieal. 

 The micrograph shows a relatively large Heltl in the basal cytoplasm of an exocrine cell. The 

 cell membrane can be seen at cm antl part of the nucleus at 11. A. lipiil inckision (/) appears in 

 close contact with two mitochondrial profiles (/«)■ The rough -surfaced elements of the endo- 

 plasmic reticulum {rs) show distended cavities and many of them contain 1-4 intracisternal 

 granules {arrows). A small cluster of smooth-surfaced vesicles is marked ss. A blood capillary 

 {be) can be seen in the upper left corner of the figure. X 25,000. 



