They face the drastic prospect of having to discard plans set out in the constitution for a new, more formal European layer of government, including an embryonic EU diplomatic service and more EU-level powers over key areas like immigration.

BBC: Mundo | Aprenda ingl��s | Voto holand��s sobre la UE

Tooth enamel begins to form in the human embryo when a specialised layer of cells, called ameloblasts, in the embryonic tooth bud secretes amelogenin proteins.

BBC: By BBC News Online Science Editor Dr David Whitehouse