These are slices of a weed stalk, I think it's a Snap Dragon stalk. I used a single edge razor blade to make a couple of thin slices across the stalk and put them on a slide. The stalk was about the diameter of wooden pencil, but thin enough that light would pass right through. Lighting was from my 550ex flash. Settings were Tv Mode, ISO 100, 1/200".
1. Nikon 10x Plan Achromat
2. Nikon 10x Plan Achromat
3. Nikon 10x Plan Achromat
4. Nikon 20x Plan Apo
Images made through a microscope. All subject types.