Public toilet seats - why the gap in front?

Q: Why are public toilet seats always "U" shaped?

Public toilets are designed the way they are for the obvious reason: men are pigs. In particular, they splash, and when they're out of the house and away from the restraining influence of their families, they splash even more — and they don't wipe up. The relevant male apparatus being in the front, this makes the front of the toilet seat (particularly the underside) pretty gross — or rather, it would make it gross, if toilet-seat makers hadn't been shrewd enough to head the problem off at the pass. Who the unsung genius was who started this practice we may never know, but it's now embodied in industry standards. Cecil was chatting with Shabbir Rawalpindiwala, chairman of the toilet-seat committee for the American National Standards Institute, and he told me that after months of solemn deliberation, he and his fellow intellectuals had definitively set the design of public (and private) toilet seats for all time, ensuring that our grandchildren will have U-shaped public potty seats too. (Actually, Shabbir heads the Committee on Synthetic Organic Materials in Plumbing Fixtures, but it'll always be the toilet-seat committee to me.) One small step for a man, another giant leap for mankind. — Cecil Adams

*TheStraightDope