then impossible to align a gathered book of sheets precisely (as one could, say, a deck of uniformly-sized playing cards), simply by tapping its edges on a table top.) Consequently, a worm gnawing straight through such a gathering would not penetrate every sheet in exactly the same position in relation to the placement of pages of text printed on them. Moreover, when the sheets were eventually folded and bound so as to align these text pages, the holes would shift out of their original dining alignments with one another. Only when paper was manufactured to uniform rectangular sizes (over a century later) could printers dispense with registration pins on the short cross, and align sheets by their edges. Until then, the position of these prehistoric wormholes was a merrie dance—as we shall see, if I have time to finish—for they’ll be closing soon.