  We compare results of previous simulations of a simple model of DNA
denaturation to the predictions of the Poland-Scheraga model. Concentrating on
the critical region of the latter model we calculate both thermodynamic
quantities and the distribution functions measured in the simulations. We find
that the Poland-Scheraga model yields an excellent fit to the data, provided
(i) we include a (singular) factor weighting the open ends of the doubly
stranded chain, and (ii) we keep the leading corrections to the finite size
scaling limit. The exponent c_1, which governs the end-weighting factor, is
fairly well determined: 0.1 <~ c_1 <~ 0.15. The exponent c, which governs the
length distribution of large loops, is determined only poorly. The data are
compatible with values of c in at least the range 1.9 <~ c <~ 2.2. From the
data it therefore cannot be decided whether the denaturation transition
asymptotically is of first or of second order. We suggest that simulations of
doubly stranded chains closed at both ends might allow for a more precise
determination of c.
