Now it's Istanbul, not Constantinople

When I was in elementary school we loaded up in a bus for a poorly thought-out trip to the Everglades. (Piling a bunch of 9-year-olds in a schoolbus for a six hour ride to look at alligators that most of us already had in their backyards was, I figure, poorly thought-out. This was right after they decided it was time to save the Everglades, but we didn't want to save a swamp in the summer.)
After a tour of the bayou and an airboat ride, they took us to a camp where, bizzarely, they had a stuffed two-headed cow. I couldn't figure this out; were they trying to show us that the toxins in the water were making cows two-headed and if so, who was the dumb farmer who was pasturing his cows in an alligator-infested bog?
I still can't figure out the two-headed cow, althought now I understand the field trip.