I have a white egg that I can see perfrect development. I have a brown and green egg that all I can of it is at one end. The rest of the egg is so dark nothing shows. It doesnt mater how you turn the egg the "clear" spot stays at that end. This spot is less than 1/4 of the egg I thought I saw somewhere that this is an air sack for the chick and this is where it will peck its way out.