brushing the dust off of the lithops

It's cloudy and cold outside but the lithops are doing their thing. Even though the regeneration advances very slowly I'm a bit worried it might be too quick. After the extra 'meat' is gone they will need water eventually, which I can't give them until there's enough sunlight for them to grow nicely.
(gracilidelineata seedlings from 2009)
(pseudotruncatella seedlings from 2008)
Thanks for your comment