In answer, we used the most convenient amniotic sac...the egg. We started last night, by soaking our egg in vinegar to remove the shell, which left us with just the membranes holding in the liquids. It was delightfully squishy. I explained the purpose of the membranes and fluids in humans, horses and other mammals, and answered lots of questions about what it feels like and how it happens. Then, we broke the egg's 'water', which resulted in squeals of delight as the contents gushed into the bowl, leaving us holding just an empty 'balloon'.
Delaney: We put an egg in vinegar and in the morning it was squishy. We scraped all the white stuff off. And then we pricked it with a knife. Then we saw the empty sac.
Brenna: I learned that if you keep rubbing off the shell after you soak the egg in vinegar, it's really neat when you poke the knife through it. We learned how the water would break when you're pregnant and how it would dribble out if you're standing up and gush out if you're lying down. The water in the sac keeps the baby from getting hurt. My favorite part was feeling the water sac before we popped it.
