The proverb is also found in a number of variant forms, some of which are illustrated below. Cf. L. pomum compunctum cito corrumpit sibi junctum, a rotten apple quickly infects its neighbour.
A roted eppel amang the holen [whole ones], maketh rotie the yzounde [sound].
[1340 Ayenbite of Inwit (EETS) 205]
A peny naughtily [dishonestly] gotten, sayth Chrysostome, is like a rotten apple layd among sounde apples, which will rot all the rest.
[1577 J. Northbrooke Treatise against Dicing 95]
The rotten apple spoils his companion.
[1736 B. Franklin Poor Richard's Almanack (July)]
The rotten apple injures its neighbour.
[1855 H. G. Bohn Hand-Book of Proverbs 514]
The police‥have a deserved reputation for uprightness. ‥But one bad apple can spoil the whole barrel.
[1979 D. Mackenzie Raven feathers his Nest 19]
Related to: associates; example, good and bad
Bibliography of major proverb collections and works cited from modern editions is available here.
