Parallels with Fleming

The invention of the terrarium depended on a chance 1829 observation by an astute observer, much like Alexander Fleming's celebrated "discovery" of penicillin's antimicrobial activity nearly a century later in 1928. Fleming was not the first to notice that mold inhibited the growth of bacteria nor did he actually isolate the antibiotic penicillin. However, he made his observation at the right time because microbiologists were using chemistry as a major tool in their research. Thus, Fleming's observation led to the isolation of penicillin in 1940 and to the 1945 Nobel prize in medicine, which Fleming shared with Ernst Chain and Howard Florey.

Like Fleming, Ward had the scientific knowledge to realize the importance of his chance observation and followed it by further experimentation. Also like Fleming's observation, Ward's successful observation depended on a series of chance events: Ward's trip to Jamaica which inspired his passion for ferns, the severe air pollution where Ward lived, Ward's failed fern wall, a fern spore in his leaf mold (perhaps provided by a dead fern from the fern wall), and the sprouting of the fern and grass before the sphinx moth hatched.