  We use our model of the small scale structure on cosmic strings to develop
further the result of Siemens, Olum, and Vilenkin that the gravitational
radiation length scale on cosmic strings is smaller than the previously assumed
$\Gamma G\mu t$. We discuss some of the properties of cosmic string loops at
this cutoff scale, and we argue that recent network simulations point to two
populations of cosmic string loops, one near the horizon scale and one near the
gravitational radiation cutoff.
