Figures 408 (upper) and 409 (lower) from Chapter 16 (Cytoplasmic matrix and cytoskeleton) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. Upper panel: Vesicles, presumably in transport along cytoplasmic microtubules in a giant axon from the central nervous system of the lamprey. Lower panel: vesicles are also clustered around microtubules (arrows) at the periphery of sites of synaptic contact. Figures from Smith, Järlfors, Beránek, J. Cell Biol. 46:199-219, 1970 (PMID:5452412). A PDF copy of the accompanying chapter is available on the ASCB's BioEDUCATE website.