Could well be bulbils, small bulbs. Some time Alliums produce these instead of flowers. Grow them on in Autumn. They take about 3 to 4 years to reach flowering size.

Thanks Owdboggy, I gather that I just plant them in the same way as 'normal' bulbs and let them do there own thing? If I plant them in pots, would I have to change the compost regularly or just feed? I was also going top have ago at planting the seeds, would the germination process take longer?