Most of the axons in the central nervous system are wrapped in myelin, a substance rich in lipids (fatty substances) and proteins. Like the coating around an electrical wire, myelin insulates and protects the axon and helps speed nerve transmission.
Potato/Semi Round Pearls. Potato pearls are some of the less expensive freshwater pearls to be found on the market, but their look is anything but cheap. You can purchase potato pearls in every color of the rainbow, and craft beautiful one of a kind creations for gifts and your own collection.
A pearl is a hard object produced within the soft tissue (specifically the mantle) of a living shelled mollusk. Just like the shell of a clam, a pearl is composed of calcium carbonate in minute crystalline form, which has been deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other shapes (baroque pearls) occur.