Figures 184 (upper left), 185 (upper right), and 186 (lower) from Chapter 5 (Endoplasmic Reticulum) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. Sarcoplasmic reticulum of the extraocular muscles of the rabbit, arranged in concentric, or sprialing cisternae. In the upper left panel, dark packages of glycogen are interspersed throughout the cisternae, whereas in they accumulate most densely at the edges of the sacroplasm in the images in the upper right and lower panels. Images by J. Davidowitz; Fig. 185 from Am. J. Pathol. 78:191, 1975 and Proc. Electron Society of America, 1976. A PDF copy of the accompanying chapter is available on the ASCB’s BioEDUCATE website.