  The spectral statistics of a Cayley-tree is numerically studied. The
statistics are non-universal due to the high ratio of boundary sites. Once the
boundary sites are connected to each other in a way that preserves the local
structure of the tree the universal statistics of the spectra is recovered. A
clear localization transition is observed as function of on-site disorder
strength, with a critical disorder $W_c=11.44^{+0.08}_{-0.04}$ and critical
index $\nu=0.51^{+0.05}_{-0.04}$. The value of $\nu$ fits nicely to its mean
field value, while the value of $W_c$ is puzzling.

Disordered Systems and Neural Networks;Mesoscale and Nanoscale Physics