Lusus Naturae
A general term for freaks or sports of nature, sometimes applied
to the area of collecting stones and minerals that appear
to contain pictures on their surfaces when cut and polished.
Such pictures may appear as landscapes or even portraits, arising
from the principle of duplication of shapes in nature, rather
as if nature draws doodles and tests out forms. The resemblance
of certain roots, notably mandrake (see mandragoras),
to human shape is a well-known example of this strange principle.