Yellow Slime Mould

Yellow slime mould, a Myxomycete.  Hayes Common, 27 March 2012.

A charming name, slime mould! But that's what it is called.  It's neither plant, animal nor fungus, though it is usually considered with the fungi by amateur naturalists.  I spotted this bright yellow blob on a fallen branch as I walked along a woodland path. On closer examination it seemed to be made up of small spheres:

Yellow slime mould, a Myxomycete.  Hayes Common, 27 March 2012.

I cut into it, but I could not see any sort of internal structure.  There is a similaly coloured myxomycete called the Dog Vomit Slime Mould, which this might be mistaken for at first sight, but that does not have the appearance of many tiny spheres that you can see here.  They might be on the end of short stalks.  So I do not have an indentification for this one.

I saw another Myxomyxete not long ago, at One Tree Hill, and that one looked like a blancmange. That didn't have any discernible structure either. But the appearance of blancmange or of many spheres is ephemeral. Two days later, I returned to this one and found only blackened remnants.  This is a piece, attached to the rotting wood it grew on.

Dead slime mould, a Myxomycete.  Hayes Common, 29 March 2012.

It does seem to have some structure now, some definite stalks, and there are probably lots of tiny spores in this mass.