It looks like slow release fertilizer.

I didn't add any fertilizer to anything yet.

I just opened a bag and the fertilizer looked like that. That's what made me think of it. Maybe some soil leftover from a store bought plant or some other potting soil that had been mixed in?

It'll be interesting to find out. Did you squish one to see what was inside?

they are the gelatinous capsules of last years time release fert ... or fert that came in a pot ...

small ones are often confused for slug eggs ....

would not be surprised if they are not filled with moisture .. but the fert is spent ...

ken

Ken, the liquid inside a CRF (controlled release fertilizer) is the fertilizer! The prills start out as as hard, dry pellets that slowly absorb moisture through micropores on the outside coating. As the pellets fill with more and more moisture, each will eventually burst....releasing the liquid contents (fertilizer).

CRF prills, even when full of water, would never be described as gelatinous. The coating is a hard semi-impervious shell that simply becomes thinner over time.

OP, I see perlite in your image, as well as collapsed, dehydrated pellets.....or something. That the perlite is there leads me to believe that the capsules are left over CRF prills. They do look like snail/slug eggs, however, especially the collapsed shells.

If they are snail or slug eggs, they will be rubbery and resist any pressure to rupture them.

If they are spent slow-release fertilizer, they will be brittle and hollow.