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."

"Perseverance is the key to success."

"Don't give up on what you believe in."

"I've been through worse."

"You learn to live with the pain."