searching emacs subdirectories

How do you make emacs search subdirectories where you have placed your own customised emacs packages?:

(if (fboundp 'normal-top-level-add-subdirs-to-load-path)
   (let* ((my-lisp-dir "~/.elisp.d/")
          (default-directory my-lisp-dir))
          (setq load-path (cons my-lisp-dir load-path))
          (normal-top-level-add-subdirs-to-load-path)))

This lets me keep my customisations in separate subdirs:
$ ls -F .elisp.d/
python-mode-1.0/ tuareg-mode-1.45.5/