theme & variation

from The Geometry of Shells

The shells of mollusks derive much of their aesthetic

appeal from the regularity of their form. From the platelike

valves of scallops to the tightly wound needle-shaped shells 

of auger snails, shells are endless variations on a geometric

theme in which an expanding figure sweeps

out a curved or spirally coiled hollow edifice. 

Because shells are growing structures built by animals, 

an appreciation of how these variations

are brought must rest on an understanding 

of how shells grow. Once we know the rules, 

we can ask why certain shapes that are compatible 

with the rules are rarely or never encountered in nature.

Geerat J. Vermeij

My mind, being tired, is thinking about other ways of being.