The message
from Amynthas contains these words:
In message , Jaques
d'Alltrades writes

I think they sound very like worm 'eggs'.

They don't sound like earthworm cocoons at all. Much more likely
to be arthropod or mollusc eggs or something added by the nursery that
supplied the plant. Looking back at the original description:

Whilst re-potting a miniature rose, I found a hell of a lot of these:
Cocoons are laid one by one as the worm moves through the soil,
not in masses. I've only found occasional ones, never great piles of
them.

If you look at my description of how they are formed, you'll see that
there is but one sphere full of fluid, which will mature into a lot of
tiny worms.

3mm in diameter.
A bit small for earthworm cocoons, except for the smaller
species.

Yellow.
Cocoons are usually brown

Hard (brittle) thin shell.
True for cocoons

Perfectly spherical.
Definitely not spherical, they are tapered at each end. The
cocoon is secreted by the clitellum as a collar and when the worm
retreats out of it the ends contract and seal. There is a rather grotty
picture at:
http://www.scarboro.demon.co.uk/garden/earthworms.htm

The vesicles line up and the male part of each worm inseminates the
female part of the other. As part of the process (It's nearly fifty
years since I studied this at school, so memory is a bit hazy) the
clitellum is worked down each worm and the sperm and ova from the female
vesicle are squeezed into the clitellum, which is shed, and its ends
close up, encapsulating the fluids.

Your memory is a bit hazy. Earthworms lie head to tail with the
male pores of one opposite spermathecal pores of the partner (and visa
versa).

I'll quote one of the bits you left out of my reply:

Worms are hermaphrodites, and they lie together 'top-and-tail', secured,
IIRC, by each squeezing under the clitellum of the other. (The short
'sleeve' about a third the way from the front.)


Sperm is exchanged and they go their own happy ways. Later over
periods weeks or months, each worm secretes a cocoon from the clitellum,
The worm retreats out of the cocoon, depositing into it ova (eggs) and
sperm from the female and spermathecal pores respectively. Fertilization
takes place in the cocoon but, although several ova are deposited only
since worms have been seen to emerge.

I take it you mean single, not 'since'? I've been potting up some things
in once-used compost and have a plethora of these eggythings. I'll pot
some up in isolation and see what emerges, and how many of them.

I don't think they're slugs' eggs and they are certainly not snails'
eggs, and in the habitat of a flower-pot that doesn't leave room for
much else.

I'm laying odds - but not eggs........

......or coccoons.

Of course, there are some worms that don't bother with meeting
up with another worm and just produce cocoons from which identical
copies of themselves emerge. (Come to think of it I don't think anyone
has checked whether the offspring are completely identical at the DNA
level.)

It's not the same as cloning: the ova would still have to be fertilised,
and as the sperms and the ova only have half a set of chromosomes each,
but with several options for the lining-up of many genes I'd guess that
the chances of the parent giving rise to identical copies of itself
would be slim.

(Ref. another plaice: Where have you got to these days?)

--
Rusty
Open the creaking gate to make a horrid.squeak, then lower the foobar.
http://www.users.zetnet.co.uk/hi-fi/