Images of desmosomes from conventional EM and freeze fracture preparations show transmembrane filaments that link two hemidesmosomes. Upper: section of a cell boundary in the ciliary epithelium of the eye; middle, cross fracture across the boundary between two ciliary epithelial cells; lower, replica of a portion of the plasma membrane of an epidermal cell from newborn mouse. Figures 90 (upper), 91 (middle) both courtesy of Giuseppina Raviola, and 92 (lower, from Peter Elias and Daniel Friend) from Chapter 3 (Junctional Specializations) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. A PDF copy of the accompanying chapter is available on the ASCB's BioEDUCATE website.