We cannot see it

Anonyme, « Color in animals-its Causes and Uses », Scientific American Supplement, n° 1123, New York, 10 juillet 1897, p. 17956.

The caddis worm, the larva of the dragon fly, abundant in the waters of our parks, wraps itself in tubes made out of particles of sand; so that while it crawls around on the sandy bottom we cannot see it.