  The galaxy image pair CSL-1 has been a leading candidate for a cosmic string
lens. High quality imaging data from the Hubble Space Telescope presented here
show that it is not a lens but a pair of galaxies. The galaxies show different
orientations of their principal axes, not consistent with any lens model. We
present a new direct test of the straight-string lens model, using a displaced
difference of the image from itself to exclude CSL-1 at high confidence.
