Whoops, bad wording on my part!
I'm fully aware of the biological classification of the different
races (better term, perhaps?
), and have often wondered what they would think if told this. I was simply asking how the different races would tell the difference between them. The fact that Elves "glowed" is interesting -- so, you see a potential Elf / Man, if he glows he's an Elf, if he doesn't he isn't? Is it only the skin that glows (so a heavily clothed humanoid can cause confusion), hence Tuor (and the reason his face gave him away?