The Professor, 1919 (unreleased)

These scenes were filmed in three days, from September 30th-October 2nd, 1919, during a halt in production of The Kid. An edited sequence plus outtakes of another sequence still survive. Chaplin (in a much different costume), plays Professor Bosco, a flea trainer down on his luck, forced to bunk down for the evening in a doss-house. This unfinished film includes the flea circus bit which Chaplin used (briefly) in 1915's By The Sea and years later in 1952's Limelight (he also considered using the bit in The Circus and The Great Dictator), but in an interview in 1957, he expressed disappointment that he'd never been able to fit the entire episode (with the doss-house & the dog, etc.) into a film.*

*Chaplin: Genius Of The Cinema/Jeffrey Vance