Quote by Elie Metchnikoff

"Man can adapt himself to anything, but he cannot adapt himself to anything without effort."

"The study of the lower organisms is the key to the understanding of man."

"Optimism is a moral duty."

"Life is a process of constant transformation."

"Gratitude makes life richer."

"A grateful heart is a happy heart."

"Respect those who came before us."

"Life's greatest treasures are the people we love"