There's a comic in which he gets annihilated and regenerates from a single surviving cell. Or from the ashes, or something. In any car, I remember it implying that his power exists beyond his physical body, because when he regenerates he isn't a mental infant - he still had his memories, even though his brain was destroyed.

However.

In the super-hero genre there's a tenancy to one-upmanship. Later artists amplify the powers of the character more and more until they are like unto gods. Superman may be the best example of this; in one series he goes and hangs out at the center of the sun for a few centuries and comes out omnipotent. If you go back to his roots in the mid-century, he was a super man, but not a god. Wolverine kept getting more and more powerful as the decades went on, until that arc where he regenerates from a single cell. I don't think the original creator imagined him being that indestructible.