That makes sense, thank you.The first answer, not the others.
Yeah, definitely a fleam. It seems to have been a feature on many of the older Sheffield knives too. The fish tickler of the 1850's
That's reasonable too. Why would you bleed an animal. Snake bites? Local shepherds used Agave thorns to do that after snake bite. Then the used thorns would be thrown away because there would be poison left on them.For bleeding people they used straight razors (barber's razor), or leeches (bloodsuckers).