Which end of the egg comes out of the chicken first?
On a recent afternoon around the lunch counter, my colleagues and I were discussing the attributes of the chicken egg when someone asked, "Which end of the egg comes out first, the round end or the pointed end?" Of course we all took a position, and while wagering of serious money did not take place, our reputations are on the line. I naturally thought of you to answer this question.
My initial thought was: these guys have been spending too much time playing the nickel slots. The more I thought about it, however, the more this question began to nag. At last I turned to Cornell University professor Kavous Keshavarz, poultry czar on the Straight Dope Science Advisory Board. According to Professor K., the egg initially moves through the chicken's oviduct small end first. When it reaches the uterus, however, it hardens (that is, the shell calcifies), rotates 180 degrees, and makes the rest of the trip big end first. This may sound like doing it the hard way, but actually it's the most efficient way to push the egg. When the muscles of the chicken's uterine and vaginal walls squeeze the egg's small (i.e., back) end, it squirts forward and out into the cold cruel world.