I suspect it is a species of Physalacria. It is a genus that I had long wanted to see and a few months ago found three of the same 1-2mm white balls on some wood in a old pile of woody prunings in my back yard. At first I thought it was a myxomycete new to me, but not so. I kept that bit of wood moist in a sealed tub and over some weeks harvested a good lot of specimens. They are rarely more than 2mm in diameter, are white to creamy and are hollow balls on short stalks. The spore-producing basidia line the outer surface but there are also abundant cystidia, which show macroscopically as very short bristles. With a macro lens they may photograph fairly well and one of your photos seems to show an abundance of bristles. You might want to see if you can add a crop showing the bristles. Some time in the next week or so I will have a go at identifying my specimens.