As promised, though somewhat delayed by my mother having septicaemia, a picture of what I found in my 45X fluorite objective. It was taken with my Canon DSLR and a stereomicroscope.
Definitely a spider’s web not mould.
As usual I had a huge argument with Adobe Elements 10. I hate it with a passion and I’m going to buy Helicon focus instead, but never mind. We have photographic evidence of the spider. The spider herself has gone. She probably starved to death.
Now I have photographed the spider’s web I can clean the objective. I’m curious to see how well it has survived being home to an arachnid.
PS. My mother has recovered.