MONOCOT SEED
This is a longitudinal section through a wheat fruit (it has the ovary wall tightly fused to the seedcoat). In many grasses the cotyledon is also called the scutellum (Scut). It does not even look like a leaf. It acts as an absorptive organ. While the embryo germinates the cotyledon (scutellum) absorbs nutrients from the endosperm.
This occurs in corn as well. Here is a kernel of corn. This kernel is actually the product of a carpel and is therefore a fruit. The ovary wall is very thin. Most of the kernel is seed. You can see the outline of the cotyledon within the kernel. The area is much lighter in color than the rest of the structure.
Here is a picture of a germinating corn kernel. You can see the radicle (embryo root) growing downward. The epicotyl is growing upward. You can see the coleoptile which acts as a protective sheath covering the growing shoot. Underneath you would find a number of young leaves.