I'm 15 and I noticed that there is a clump of veins/vein near my right testicle. You can clearly see it through the scrotum, and if i put my testicles on my palm and separate it, i can even grasp this "Clump". It feels like its not actually on it, but next to it. I looked online and found...
I'd say George since he understood lennie, and killed him "peacefully" so the others wouldn't. But, i think that is too blase, there has to be something else.