PORTER ON PEDIGREES, by Alan Porter <P> Harlan's Holiday, who currently ranks second on the leading freshman sires list, is one of several grandsons of Storm Cat who are proving themselves as sires. His top runner to date is Into Mischief, winner of the CashCall Futurity (gr. I) at Hollywood Park on Dec. 22. Harlan's Holiday has also been represented by stakes winners Tasha's Miracle, Bear Holiday, P.S.U. Grad, and Harlan's Song.