The only features that by inspection grossly and examination histologically distinguish the breast from the rest of the skin and subcutaneous fat are nipple and areola. All elements present in the breast are found elsewhere in the skin and subcutaneous fat. The very special function of the breast, namely, production of colostium by apocrine cells of mammary glands, is operative only in post-pubescent females; in pre-pubescent females and males, and in post-pubescent males, the breast has no special function.