Anyway, I will write something on carrot transplanting later. It fades into the background compared to what I found when inspecting the 20 or so little pots for transplant - some sort of water-crystals, slime or jelly. The little pots (about 6 in high, 4 in wide, black plastic ones, on a bookshelf in the garden) were filled with soil on shortly before.
A few slime mould links:
I'm pretty sure it isn't a slime mould; it could be a jelly fungus, it could be water-retaining crystals in the fertiliser that were accidentally in a clump and not distributed.
I don't think that it isn't frogspawn. Whatever it is, it has coagulated, because the compost was sieved to 3-4 mm before going in the pots. It was in the middle pot of the top row, at the back away from the sunlight (i.e., probably the least exposed and most temperate position in the whole bookshelf).
For comparison the brown granules are wet tea leaves. This stuff appeared before I put the tea leaves on. I can't work it out. Any help?