Blood will tell

Posted by Victoria S Dennis September 14, 2010 at 20:47In reply to Blood will tell posted by Gary Martin on September 14, 2010 at 08:54:

I've heard the saying "blood will tell" used a couple of times. Does anybody know its origin?

I've heard it as 'blood will out', or 'bad blood will out', but I don't know the origin.

"Blood" in this context means "heredity"; this proverbial phrase means "it's breeding that counts". Either in a good way, as implying that a dog from a long line of champion sheepdogs should turn out to be a good sheepdog itself; or in a bad way, as implying that anyone whose grandfather was a drunk and a gambler is bound to turn out to be a Bad Lot himself. (VSD)