The Isles of WHAT?

I was taking my daughter to the bus stop this morning, and we noticed a lot of tree debris on the ground. She asked me what it was for and I explained how trees and bushes grew. Then she asked me how trees and bushes lost branches, and I explained that too, mentioning termites and vines, etc., commenting that vines were parasites. She asked me what a parasite was, and I explained, using termites as examples of symbiosis, as opposed to vines and tapeworms which were parasites. After I explained what tapeworms were, she compared them to diabetes. I explained how they were different, that tapeworms steal food before you eat it (sort of), but diabetes is the body's inability to produce some needed substance to use food properly.

"Insulin," she says.

"Yes," I reply. "It's produced by some cells on the spleen, I think."

"No," she says, "It's the pancreas. They're called the Isles of Langerhans. I read about them in one of my Muse magazines."

My daughter is 8.