Lucretius in his third [book] ‘De Rerum Natura’. The hands, nails and teeth were (165) the weapons of ancient man.
They also use for a standard a bunch of grass tied to a pole (167).
[Footnote: Lucretius, de rerum natura libri VI were printed first about 1473, at Verona in 1486, at Brescia in 1495, at Venice in 1500 and in 1515, and at Florence in 1515. The numbers 165 and 167 noted by Leonardo at the end of the two passages seem to indicate pages, but if so, none of the editions just mentioned can here be meant, nor do these numbers refer to the verses in the poems of Lucretius.]
Taken from The Notebooks of Leonardo da Vinci edited by Jean Paul Richter, 1880.