it seemed that with each twitch and tic that heart , though green , was full and quick , for underneath the paper leaves this toad-destroying damocles was smitten with a verse : `` when first the trees did start to spread their roots through dust and ochre red ; when forest 's sultry canopy made green the thunder-croaking sky : when there were shapes upon the boughs that fell and walked and took up ploughs : when all this happ 'd and man was cast of ochre and the acorn mast ; it was that he first learned to gib and call this fresh-walked earth his crib to draw his words from tiers of rye , to cast a newly tearless eye on all that he surveyed : that surely he believed was made some paradise amongst the sheaves some newfound font to pen his leaves of history sublime : yet forth from this new measured time there marched a second measure grave with at its head the will to stave those of others , to cleft and beat and leave the birds of prey to greet them to the leaden clouds ; as though they found in fields of rye and ochre some new crimson dye to stain their hempen shrouds .