"I am not a very good speaker, but I hope my work speaks for itself."

"I am not a hero. I just happened to be in the right place at the right time."

"It is not difficult to make microbes resistant to penicillin in the laboratory by exposing them to concentrations not sufficient to kill them, and the same thing has occasionally happened in the body."

"The mold was a lucky accident, but the observation was not."

"It is the lone worker who makes the first advance in a subject; the details may be worked out by a team, but the prime idea is due to enterprise, thought, and perception of an individual."