Thanks for the input Al, the actual protocorm is nice and green so I
doubt it's doomed (yet). Other seeds have plumped up then died in the
same flak so I understand what you mean. All it is, is just an
elongated cell projecting upwards from the clump of cells. Will keep a
close eye on it and hopefully this will turn out to be a leaf type of
thing. Actually I don't have any charcoal in the medium and since
there are so phew protocorms in the flask, the distance between them is
quite respectable.

Naïve Nigel (thanks Mick for your inestimable input and your hawk-eye
vision at spotting typos)