Whereabouts are they? A lot would depend on the local climate.

Im in the Florida Keys...

Picture of the inside

To be clear, I'm talking about Adonidia merrillii, Manilla/Christmas Palm. I've never cut any open so don't know how they should look inside. Generally, they are quite easy to grow from seed. But if the seed is old and has been laying in the full sun for a long time it may be dead. I've collected them around the time they fell and got a very good germination rate. Only problem was that some sort of rodent also liked the seed and when it found the newly sprouted seedlings managed to destroy most of them before I managed to protect the rest. It's worth a try to germinate them, but if you don't get results in about 4 weeks then probably they aren 't viable.