How to combine several functions in a single oct-file?

Dear Octave community,

I noticed that "which arrayfun" points to cellfun.oct (octave 3.6.0). This means that both arrayfun and
cellfun are stored in a single oct-file. Now I wonder how octave knows that it finds arrayfun in
cellfun.oct? Does octave load all oct-files on startup? I thought that a function "foo" has to be located
in foo.m, foo.oct or in the same m-file as the calling function.

Background: My control package has dozens of oct-files and I like to combine them in just a few oct-files.
They all use the SLICOT Fortran library and I compiled the required parts of it into every single oct-file.
I think it would be better if the Fortran code would be stored in one big oct-file that offers all the user
functions. Like cellfun.oct.

Thanks for any insights and best regards,
Lukas