Chiral symmetry breaking in stirred crystallization of sodium chlorate (NaC
lO3) occurs via the production of secondary crystals from a single "mother
crystal." Martin, Tharrington, and Wu [Phys. Rev. Lett. 77, 2826 (1996)] in
vestigated this phenomenon and concluded that it was mechanical crushing of
a crystal by the stir bar, not convection, that produces secondary crystal
s from a single crystal, Here we report the generation of secondary crystal
s of sodium chlorate when a saturated solution of sodium chlorate is simply
made to flow over a sodium bromate (NaBrO3) crystal. This clearly shows th
at fluid flows alone can generate and disperse secondary nuclei.