Thank you, everyone.
As these are my first attempts at growing anything from seed, I'm a bit like an anxious mother !
Cheryl...I'm too much of a novice to really suggest anything, but there are varying accounts about freshness of seeds and the right amount of heat.
I did find that the Arabicum seeds I bought appreciated a slightly higher temperature and maybe a bit more moisture, and they are growing very slowly.
The Somalense were up and out within three days.
The Obesum seeds I have are taking three to four days to germinate, with a few taking quite a bit longer.
They are all in an ordinary heated propagator (no thermostatic controls) in a bright (but no full sun) place. As it's getting dark quite early here now, I'm adding some extra light in the early evenings - not sure if that's helping but it doesn't seem to be harming ! The light is a full spectrum daylight type. The seeds themselves were bought from someone who imports them, so they have had several journeys (and an unknown length of time) before arriving with me. That could explain the very slow growing (and two out of five germinating) Arabicums, I guess.
I'm not sure how late in the season would be too late, it's getting very Autumnal here in the UK.
The ebay sellers here in the UK are mostly selling off their excess seeds at a discount now though, stating "end of season" as a reason. I'm planning on using all the seeds I have left as soon as possible.
Hopefully I'll get some more photos taken later today.
