The new definition of fractional statistics given by Haldane can be
understood in some special cases in terms of the Riemann-Roch theorem.Comment: 38050 Povo, Trento and Division de Physique Th\'eorique, IPN, 91406
Orsay Cedex, 19 pages, IPNO/TH 94-11, SISSA/27/94/EP,UFT/32