We also form the sensory cells as well as melanocides. So melanocides are those cells that not only give us pigment but also protect us from UV radiation that comes from the sun. So the integrationary system found on the outside is formed from the ectoderm, which is the outermost layer of that developing embryo. These lipurpose cells shown in this diagram. Now, we also actually form different types of structures that are found inside that developing embryo. The question is, how does that happen?