▁was ▁an ▁im itation . ▁W ode house ▁wrote ▁in ▁the ▁letter , ▁" I ▁have ▁just ▁written ▁to ▁a ▁j ew eller ▁asking ▁for ▁professional ▁advice ▁on ▁the ▁point . ▁What ▁I ▁want ▁to ▁know ▁is ▁Can ▁anyone ▁be ▁taught ▁to ▁spot ▁im itation ▁j ew els , ▁or ▁do ▁you ▁have ▁to ▁have ▁some ▁sort ▁of ▁fla ir ?" ▁The ▁problem ▁is ▁resolved ▁in ▁the ▁final ▁version ▁of ▁the ▁novel , ▁in ▁which ▁Je e ves ▁states ▁that ▁he ▁learned ▁while ▁studying ▁under ▁a ▁cousin ▁in ▁the ▁profession ▁that ▁cult ured ▁p ear ls ▁have ▁a ▁core . ▁ ▁This ▁story ▁marks ▁the ▁second ▁time ▁Je e ves ▁disapp ro ves ▁of ▁Bert ie ▁having ▁a ▁m oust ache . ▁The ▁first ▁time ▁occurred ▁in ▁" J ee ves ▁and ▁the ▁Hard - bo iled ▁E gg ". ▁ ▁At ▁one ▁point ▁in ▁the ▁story , ▁Bert ie ▁def ends ▁his ▁m oust ache ▁by ▁stating ▁that ▁a ▁m oust ache ▁looks ▁good ▁on ▁the ▁actor ▁David ▁N iven , ▁with ▁Je e ves ▁rep lying ▁that ▁a ▁m oust ache ▁su its ▁David ▁N iven ▁but ▁not ▁Bert ie . ▁David ▁N iven ▁had ▁port rayed ▁Bert ie ▁Wo oster ▁( with ▁a ▁m oust ache ) ▁in ▁the ▁earlier ▁ 1 9 3 6 ▁film ▁Thank ▁You , ▁Je e ves !. ▁ ▁Public ation ▁history ▁In ▁addition ▁to ▁its ▁UK ▁and ▁US ▁publications , ▁this ▁story ▁was ▁also ▁published ▁under ▁the ▁title ▁Double ▁Je op ard y ▁in