My onion seeds

I gathered some onion seeds from onions that I had let go to seed.
Last weekend I sowed a few just to see what would happen, well they're germinating like mad, I of course dont know what variety they are.

So, now that I know that my seeds will germinate, which was the object of the exercise, what should I do with them.
At the moment they're in a small seed tray & I dont really have any space in our very tiny greenhouse (6x2)

Thanks chaps/chapesses

(I assume it is an autumn variety?)

Can't say because they have been naturally pollenated so could be crossed with anything 

I'll do as you suggest though & plant out a few of them in the open & again "see what happens" There aren't any leaves as such just the initial shoot about 10mm poking from the compost.

Thanks