βορβόρῳ δ' ὕδωρ λαμπρὸν μιαίνων οὔποθ' εὑρήσεις ποτόν → once limpid waters are stained with mud, you'll never find a drink
See continuance.
that which comes next to: P. τὸ ἑξῆς (gen. or dat.).
the continuation of the argument: P. ὁ ἑξῆς λόγος.