One opportunist who stayed was Octavius Decatur Gass.
( ( One ( opportunist ( who stayed ) ) ) ( ( was ( Octavius ( Decatur Gass ) ) ) . ) )
(ROOT (S (NP (CD One) (NN opportunist) (SBAR (WHNP (WP who)) (S (VP (VBD stayed))))) (VP (VBD was) (NP (NNP Octavius) (NNP Decatur) (NNP Gass))) (. .)))
One opportunist who stayed went by the name Octavius. 
( ( One ( opportunist ( who stayed ) ) ) ( ( went ( by ( the ( name Octavius ) ) ) ) . ) )
(ROOT (S (NP (CD One) (NN opportunist) (SBAR (WHNP (WP who)) (S (VP (VBD stayed))))) (VP (VBD went) (PP (IN by) (NP (DT the) (NN name) (NNS Octavius)))) (. .)))