The lottery

We are led to believe there is some kind of tradition involved but we are never told why. Old Man Warner, warns of ominous fortunes if they should stop practicing the lottery, "Lottery in June, corn be heavy soon." So did the lottery have something to do with an agricultural sacrifice? We are never sure which is the point of Shirley Jackson's famous story. It is ironic that these people are slowly loosing the trappings of their tradition except for the actual killing. Perhaps the morbid primal human fascination with killing is the purpose for the lottery in the village.