but it leaves him in the dark, as all criticism dealing only with transmitted variations must do, as to the amount of correspondence between the best transmitted text and the text of his author. These cases correspond to such limited parts of the documentary evidence of more adequately attested texts as represent single stages of textual history.
74. In those rare cases, on the other hand, in which extant documentary evidence reaches up into quite ancient times the process may be carried back to a stage comparatively near the autograph: but here the evidence is as a matter of fact never abundant enough for more than rough and partial approximations to the typical process described above. Here too, as always, we have to ascertain whether the confusing influence of mixture exists, and if so, within what limits. Under such circumstances any chronological and geographical information to be obtained from without has great value in interpreting obscure genealogical phenomena, especially as marking the relative date and relative independence of the several early documents or early lost ancestors of late documents or sets of documents.
75. In proportion as we approach the time of the autograph, the weight of composite attestation as against homogeneous attestation increases; partly because the plurality of proximate originals usually implied in composite attestation carries with it the favourable presumption afforded by the improbability of a plurality of scribes arriving independently at the same alteration; partly because the more truly composite the attestation, that is, the more independent its component elements, the more divergences and stages of transmission must have preceded, and thus the earlier is likely to have been the
