While I know Tolkien wasn't referring to autofluorescence when he wrote this line in the Fellowship of the Ring, it certainly still applies. Today when training on the fluorescence microscope, I became well acquainted with autofluorescence and how easily it can light the darkest of places. Since I don't work with plants, I found their strong autofluorescence exciting and and extremely useful. It allowed me to simply pluck a clover from outside the building, place it on a slide, and watch things glow. All I had to do was snap a Texas Red filter into place on the scope and watch as my little clover shone bright. Now I realize that autofluorescence can be a pain to account for and work around when you work with plants, but for simply learning to use a fluorescence microscope, it was a great asset. To my friends next door working with Arabidopsis, may the grace of the Valar be with you.