I think you will find that seedless grapes are grown on the vine as usual, but something (i dont know whether natural or in the feed they get) prevents the seed inside them from actually forming properly - so they do in essence have seeds, but its is so mushy or non-formed that it pretty much just forms part of the grape itself.
Im sure the King will correct me if I am sadly mistaken!
Bad players get lucky...Good players get unlucky. Im good...and often wish I wasn't.