IGM form a unified group and we denote their consensus by the sign Z; in the absence of I we signify the consensus of GM with £. It will be seen that in the earlier part of Book I this family is reduced to M. Here one may sometimes call on the help of Harleianus 2564 saec. xv, which we call h; this manuscript, though overlaid with the vulgate text, shows a number of striking readings which reveal a source closely related to G. At the end of the poem we lack the guidance of A, which, though not free from interpolations, is by far the most sincere witness; here the testimony of Cantabrigiensis Pembrokianus 280 saec. xii, which we call F and which in the earlier books shows more fidelity to the A-tradition than any other manuscript, is sometimes useful, though it cannot be relied on without grave reservations. Editors usually quote Monacensis 8122 (D) as if it were a primary witness; it is nothing of the sort, but rather a much corrupted and interpolated offshoot of the A-tradition diluted by some contamination from Z. We use ω to indicate the mass of the vulgar manuscripts and ς to indicate some of them