Richard Semon (The Mneme, 1904, 1921) wrote …

“When an organism has been temporarily stimulated and has passed, after the cessation of the stimulus, into the condition of ‘secondary indifference,’ it can be shown that such organism — be it plant, protist, or animal — has been permanently affected. This I call the engraphic action of a stimulus, because a permanent record has been written ot engraved on the irritable substance. I use the word engram to denote this permanent change wrought by a stimulus; the sum of such engrams in an organism may be called its ‘engram-store,’ among which we must distinguish inherited from acqired engrams. The phrnomena resulting from the existence of one or more engrams in an organism I describe as mnemic phenomena. The totality of the mnemic potentialities of an organism is its ‘Mneme.’”