serving files with no extension in their name

Does jigsaw refuse to index/serve files that do not have some
extension (.txt, .html) in their names?  I have several thousand files
with no extension that I would like jigsaw to serve as text/plain.

I have done the re-index operation on the directory, and those files
that do have extensions are correctly indexed and served.  But those
without extensions are ignored.  Can someone please recommend a fix?
Thanks.

-Kevin