Today on How Do Chickens Work: What is THAT weird part of the egg?
Here we have a bowlful of farm-fresh eggs. These eggs' shells had some irregularities that might have allowed bacteria inside the egg. So I'm about to make the world's most thoroughly-cooked scrambled eggs--any bacteria will surely die, but the eggs will have the consistency of cheap chewing gum after three hours of dedicated jawing. But the dogs think that's haute cuisine, so everybody wins.
Before I beat these eggs and cooked them down to jaw-aching rubber, I took their picture so I could ask this question: Can you tell which eggs are fertilized? You may think the answer looks so obvious that you suspect a trick. You'd be right.
Here's the answer (you can click to enlarge):
The pale little 'bull's eye' appears after the egg is fertilized. That is where the embryo would begin to develop, if it were going to. The much more obvious white globules are just an egg part; they are there whether the egg is fertilized or not.
How's that for egg facts?