[BusyBox] does tar not extract arguments recursively?

[Robert P. J. Day]

  i might be missing something obvious, but BB's tar doesn't seem
to extract arguments recursively.  i have a slackware-style tarball,
whose contents are, in part:

# tar tvzf blah.tgz
...
drwxr-xr-x 0/0         0 2004-04-05 14:07:37 install
-rw-r--r-- 0/0       185 2004-04-06 03:51:15 install/doinst.sh
-rw-r--r-- 0/0       438 2004-04-06 03:43:10 install/slack-desc
-rw-r--r-- 0/0        36 2004-04-05 14:07:37 install/slack-required


so note that the tarball contains the directory install/ and 
some files.

  if i try to extract just the "install" directory, i get:

# tar xvzf blah.tgz install
install

and that's it -- just the directory, not its contents as well, which
is certainly what i'd get with regular GNU tar.

  thoughts?  is this the expected behaviour?

rday