  Resonant spin--flavour conversion of neutrinos (RSFCN) in twisting magnetic
fields might be at the origin of the apparent anticorrelation between the
$^{37}$Ar production--rate in the Homestake solar neutrino detector and the
solar activity. Moreover, it can account for the results of all solar neutrino
experiments reported so far including the recent results of GALLEX and SAGE.
