This is my 1st time incubating duck eggs, and I'm not sure about their progress. It is day 17, and out of 18 eggs 13 have the nice dark center. The others were quiters, and I got rid of them. My question relates to candling. I can see the air pocket on the top. The center is a big dark blob with veins running around the edges. The bottom, er, top, er, the other end...is cloudy. Is this the yolk? I expected the dark to take up the entire egg sans the air sack. All of them are like this. Is this normal? I'll try to get pics up soon. I'm just not used to being able to candle the eggs...quail eggs are impossible to see through! It is fun to be able to watch them change.