genpath not working?

[oxyopes]

Hi, genpath should generate a path with input dir and its subdirs.
In the example bellow it does not work. Is this function really working?

octave-2.9.9:30> genpath('/usr/local/share/octave/2.1.73/site/m/octave-forge');
octave-2.9.9:31> which legend
which: `legend' is undefined
octave-2.9.9:32>
addpath('/usr/local/share/octave/2.1.73/site/m/octave-forge/plot');
octave-2.9.9:33> which legend
legend is the user-defined function from the file
/usr/local/share/octave/2.1.73/site/m/octave-forge/plot/legend.m

The various subdirs from
/usr/local/share/octave/2.1.73/site/m/octave-forge
also do not appear at the output of path function.