  A metric is introduced on the two dimensional space of parameters describing
the Ising model on a Bethe lattice of co-ordination number q. The geometry
associated with this metric is analysed and it is shown that the Gaussian
curvature diverges at the critical point. For the special case q=2 the
curvature reduces to an already known result for the one dimensional Ising
model. The Gaussian curvature is also calculated for a general ferro-magnet
near its critical point, generalising a previous result for t>0. The general
expression near a critical point is compared with the specific case of the
Bethe lattice and a subtlety, associated with the fact that the specific heat
exponent for the Bethe lattice vanishes, is resolved.
