I don’t know how the nerve endings work but there was a blues man who had his finger tip reattached with just a wrapping of balm and spider webbing.
http://www.chron.com/entertainment/music/article/Earl-Gilliam-sings-lives-the-blues-1725886.php
He holds up his “trigger finger,” a long, brown, spidery digit that has pounded out blues songs on a keyboard for the better part of seven decades. The tip of the finger is positioned at a permanent right angle, the result of a lawn mower accident when he was a kid. “My mother didn’t believe in doctors,” he says. So she reattached the fingertip, splinted it using spider webs as a wrap and soaked it in vinegar. “That’s just the way it healed,” he says, smiling. “Told you, she didn’t believe in doctors.”
Wow, spider webs! It would be interesting to know if the nerves reconnected. I’m pretty amazed that his body was able reestablish the blood supply to the tip quickly enough to keep it alive.