periosteum

luukalvo A membrane surrounding a bone.
(quote-book)|year=1997|page=131|isbn=978-0-683-06225-0|passage=Periosteum and endosteum are connective tissue sheaths of bone. (..) The periosteum is a layer of connective tissue covering the external surface of a bone. The periosteum may be divided into two components: / a. An outer fibrous layer consists of dense irregular connective tissue. / b. An inner cellular layer consists of osteoprogenitor (osteogenic) cells.
(quote-book)|year=2011|page=52|isbn=978-1-4398-6691-7|passage=The periosteum is constrained and interrupted by tendons, ligaments, and fibrocartilage, whereas the endosteum is awash with hematopoitic bone marrow(nb..).