Geometry can be found underlying all, or nearly all, the forms in nature. One learns this from D'Arcy Thompson's book "On Growth and Form," a favorite of Tony's, and from Jay Hambidge's "Elements of Dynamic Symmetry," another favorite of his. Of course one can learn this just from observation, if one looks intently enough. No form in nature is a perfect example of the geometry it is a case of, but when you average the many examples of one form - many examples of the skeletal structure of a bird's wing, or the arrangements of leaves on a stem, or cellular or atomic forms - you get the perfection we normally ascribe to man-made geometry. Of course, all man-made geometry is natural, because we are nature.