And notice that this entire structure here is that developing embryo. It's that developing fetus. So the red portion is the actual embryo along with this green portion and the blue portion, the red portion is basically that middle layer, it's that Messider. And the Messider will basically form the musculoskeletal system, the cardiovascular system, the excretory system, the reproductive system, everything's found in between the green layer and that blue layer. Now the blue layer is found on the outside. It's the external layer.