Brown adipose tissue is present in small mammals (e.g., mice) and in newborn humans. Most of it disappears in adult humans. The cells in both types of fat are called adipocytes although they differ in origin, structure, and function in the two types of tissue.
On the left hand, index finger. It's not the index finger you wear it on. Left hand, ring finger. The finger that you would wear a wedding ring on.
The use of the left-hand pinky finger as the wedding ring and royal signet or initial ring of the British Royal Family is shrouded in family secrecy. Nevertheless, it is an ironclad tradition dating back to the sons of Queen Victoria.