I was telling my boyfriend about how I can tell chicks are developing in the eggs in my incubator because they are gaining weight -- and he laughed at me, like I'm some silly girl. He says the egg can never weigh more than what it does when it is laid. That the material inside remains the same. I say that's nuts -- that as the chick develops, as a maybe develops, it brings mass, density to the inside of the egg. I say that the skin and bones and heart and brains and blood of the chick have more weight than mere yolk and albumin. Tell me I am right.