I'm sorry to bother people again, but, continuing with the ELB I posted about a little while ago, in getting rid of the cambium and thinning sapwood a bit I find something I don't think I've seen before in yew - fine black lines in the sapwood, I hoped they were just on the surface but they run down at least through the 3 layers I have removed so far.
I'll try and add a picture or two, though ut was hard to get them to show up.
Any views on what they are, and what to do (if it's not completely fatal) will be welcome.