If yonder raindrop should its heart disclose,
Behold therein a hundred seas displayed.
In every atom, if thou gaze aright,
Thousands of reasoning beings are contained.
The gnat in limbs doth match the elephant.
In name is yonder drop as Nile’s broad flood.
In every grain a thousand harvests dwell.
The world within a grain of millet’s heart.
The universe in the mosquito’s wing contained.
Within that point in space the heavens roll.
Upon one little spot within the heart
Resteth the Lord and Master of the worlds.
Therein two worlds commingled may be seen . . .

— The Sage Mahmoud Shabistari,
in the Fourteenth Century
(The Secret Garden)

This miniscule world of the sand grains is also the world of inconceivably minute beings, which swim through the liquid film around a grain of sand as fish would swim through the ocean covering the sphere of the earth. Among this fauna and flora of the capillary water are single-celled animals and plants, water mites, shrimplike crustacea, insects, and the larvae of infinitely small worms — all living, dying, swimming, feeding, breathing, reproducing in a world so small that our human senses cannot grasp its scale, a world in which the microdroplet of water separating one grain of sand from another is like a vast, dark sea.

— Marine Biologist Rachel Carson,
Twentieth Century
(The Edge of the Sea)