Figure 360 from Chapter 15 (Cytoplasmic Inclusions) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. Leydig cell from a reproductively active ground squirrel, Citellus lateralis. Physiological state can influence the extent to which lipid is stored in the same cell type. Here, lipid droplets are abundant, but during the quiescent phase of the breeding cycle, these cells would contain only one or two enormous lipid droplets that would occupy much of the cell body. A PDF copy of the accompanying chapter is available on the ASCB’s BioEDUCATE website.