Figures 424 (upper) and 425 (lower) from Chapter 16 (Cytoplasmic matrix and cytoskeleton) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. The nucleus and adjacent the manchette rodent spermatids. The microtubules of the manchette are joined together in an irregular pattern by slender cross bridges (arrows). A PDF copy of the accompanying chapter is available on the ASCB's BioEDUCATE website.