Definition of secede - withdraw formally from membership of a federal union, an alliance, or a political or religious organization Definition of secede - withdraw formally from membership of a federal union, an alliance, or a political or religious organization
A shell casing is a piece of ammunition that is made of metal. It is often brass, but it can be made of other metals as well, and the more durable the better. Shell casings can be made from any kind of ammunition that is fired from a pistol, rifle or shotgun. It is not a bullet, but it is a piece of the larger ammunition mechanism that is loaded into the chamber to be shot.
The shell itself is made of bone, and the outer covering of the shell is made of keratin, much like human fingernails. Each shell is made up of sections called scutes. As the turtle grows, new layers of keratin are formed around the outer edges of each scute, looking much like the growth rings of a tree.