# Biology

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**.