Let D be a bounded symmetric domain realized as the open unit ball of a com
plex Banach space E and denote for every a is an element of D by s(a) the s
ymmetry of D about a. We show that for every boundary point c is an element
of partial derivative D the locally uniform limit s(c) := lim(a-->c) s(a)
exists as holomorphic map s(c) : D --> E and has values in the boundary par
tial derivative D of D.