In Biomathematics (4) we develop mathematics for cellular and molecular shapes.

The picture shows a mathematical description of tubular myelin (from a rat lung).

In the description of the ultrastructure of the brain, rods of axons or dendrites cluster to a geometry we call rod packing(2,5). The tetragonal symmetry as described in Fig 8a and b in ref 5 we show here as a projection along the tetragonal c.

Rat lung

Rod packing of axons (5)