Figure 9. (a) Diagram from Huxley (1957b) showing the hexagonal array of myosin and actin filaments (he called them primary and secondary filaments) and how different longitudinal sections will appear.

A section along A-A, and parallel to the fibre axis, which would be as if viewed from the top of the figure, would show alternating myosin and actin filaments, as in the right hand diagram in (a), and as observed in (c). A very thin section along B-B in (a) would show myosin filaments with two actin filaments between them, as observed in the section in (d). Note the clear H-zones in (c, d), where the actin filaments do not penetrate. Reproduced with permission.