Over the years I've cut up an awful lot of oranges and lemons and you can guarantee that you'll find at least one pip in each.
Over the last few years I've started cooking Mexican food quite a bit and this, in turn, has led me to cut up quite a few limes. I must have cut into at least a hundred or so limes and I'm yet to encounter a single pip. Do limes not have pips? I'd always assumed they were reproductively similar to oranges and lemons. Am I missing something obvious?