As noted earlier, the translations of these four treatises have been made from Kühn's Greek text with its accompanying Latin version (VI.836–80K, VII.1–272K). The Kühn text as a whole has been much criticized for its supposed inaccuracy, not least by those using it as a basis for translation, but is, in the case of these four treatises, the only post-sixteenth century Greek text available. There are three other possible sources of the text: (i) early manuscripts, as listed by Diels; (ii) Arabic versions; (iii) Latin versions, as catalogued by Durling. In the present case, the Florentine manuscripts Laurent. plut. 74.16 and 74.12 have been examined, but no significant changes to the Kühn text have been made on the basis of this. The Latin versions used, apart from that included in Kühn, are all those listed by Durling other than the anonymous one. Whatever the precise relationship to the original, the text as presented in the Kühn volumes contains very little that is uncertain or unclear to the extent that textual emendation seems mandatory. Certainly, the preparation of a new Greek text in the form of the estimable, but only very gradually accumulating, CMG series would be a most worthwhile endeavour. This, obviously, is not what is attempted here. Points of apparent textual difficulty are indicated in the footnotes as they arise, as are sentences difficult of comprehension – although these are arguably as likely to be due to Galen's style, also a target of criticism by some, as to errors in transmission of the text.