Editorial policy is an important factor: I certainly wanted to record such conjectures as carefully as I could, and not all editors give that equal priority. But I wonder if there are not other factors that may operate too. To take the case of NQ, it may well be relevant that (a) the editio princeps was based on a relatively late and poor manuscript, and so were most or all of the manuscripts seen by early editors; (b) the manuscripts from which the modern stemma can be reconstructed were discovered, or their importance recognised, relatively late – late 19th and 20th centuries for the most part; (c) in the early centuries a series of distinguished editors and textual critics applied their minds to the text: I think of Erasmus, Muretus, Gronovius, Bentley and others – and Fortunatus, though not a ‘big name’, did important work on the text. They do not all feature equally prominently on your list, but it meant that simple errors in the textus receptus stood a good chance of being corrected.
I guess these suggested factors will have different significance in the case of different works. Factor (a) will also apply to many other Latin works; but factors (b) and (c) may be more variable – I just don’t know. Hence in general I would expect that there are more ‘confirmed conjectures’ to be discovered, but perhaps not with the same frequency in every author or every work.
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I was focusing on manuscripts that are closer to the archetype but have only come to light in comparatively recent times; but there is another case, of later manuscripts that may be very remote from the archetype (where there is a single archetype, of course!) but which contain perceptive conjectures that have not come to the attention of earlier editors. I remember a colleague suggesting to me that I might look at the late Italian manuscripts of the NQ to see if any of them contained good conjectures; but I am afraid I never did it systematically – though today, with so many manuscripts available online, it would be easier to make a start than when I was working on the NQ manuscripts over 40 years ago.
—Harry Hine