Passage 6.26.6
ἡ δὲ Ἠλεία χώρα τά τε ἄλλα ἐστὶν ἐς καρποὺς καὶ τὴν βύσσον οὐχ ἥκιστα ἐκτρέφειν ἀγαθή. τὴν μὲν δὴ κανναβίδα καὶ λίνον καὶ τὴν βύσσον σπείρουσιν ὅσοις ἡ γῆ τρέφειν ἐστὶν ἐπιτήδειος· οἱ μίτοι δέ, ἀφʼ ὧν τὰς ἐσθῆτας ποιοῦσιν οἱ Σῆρες, ἀπὸ οὐδενὸς φλοιοῦ, τρόπον δὲ ἕτερον γίνονται τοιόνδε. ἔστιν ἐν τῇ γῇ ζωύφιόν σφισιν, ὃν σῆρα καλοῦσιν Ἕλληνες, ὑπὸ δὲ αὐτῶν Σηρῶν ἄλλο πού τι καὶ οὐ σὴρ ὀνομάζεται·
The land of Elis is good above all for producing crops and especially excels in growing fine flax. Hemp, linen, and fine flax are indeed sown by those whose land is suitable for cultivation; however, the threads from which the Seres make their garments do not originate from any plant fiber, but are produced in a different, unique manner. There exists in their country an insect, which the Greeks call "ser," though among the Seres themselves it bears another name entirely, not "ser."