The Chians are bad, not one bad and another not, but all bad — except Procles, and Procles is a Chian.
Καὶ τόδε Δημοδόκου· Χῖοι κακοί· οὐχ ὁ μέν, ὃς δ᾽ οὔ·
πάντες, πλὴν Προκλέους· καὶ Προκλέης δὲ Χίος.
πάντες, πλὴν Προκλέους· καὶ Προκλέης δὲ Χίος.
Original text (Ancient Greek)
Source, in full
Palatine Anthology, bk. 11, no. 235. Edited and translated by W. R. Paton, The Greek Anthology, vol. 4 (London: William Heinemann, 1918) pp. 182–183. Paton's note: "There is another couplet identical with this except that the Lerians are substituted for the Chians and that the saying is attributed to Phocylides." The paraphrase – whether by Porson or Bentley – is well known
Notes from Wikiquote
The Germans in Greek are sadly to seek,
Except only Hermann, and Hermann's a German.