We separate oil-olives as terumah on behalf of preserved olives, but not preserved olives on behalf of oil-olives; and uncooked wine on behalf of cooked wine, but not cooked wine on behalf of uncooked wine. This is the general rule: Whichever [two species] are kilayim with each other, one may not separate terumah from one on behalf of the other, even from superior pro-duce on behalf of inferior produce; and whichever [two species] are not kilayim with each other, one may separate terumah from the superior produce on behalf of the inferior produce, but not from the inferior produce on behalf of the superior pro-duce. But if he designated terumah from inferior produce on behalf of superior produce, his terumah is terumah, except for zunin on behalf of wheat, for [zunin] is not a food. Cucumbers and kirbies are one species. Rabbi Yehudah says: [They are] two species.