T and B cells. Lymphocytes originate from stem cells in the bone marrow; these stem cells divide continuously, releasing immature lymphocytes into the bloodstream. Some of these cells travel to the thymus, where they multiply and differentiate into T lymphocytes, or T cells.
Cellophane is a thin, transparent sheet made of regenerated cellulose. Its low permeability to air, oils, greases, bacteria and water makes it useful for food packaging. Cellophane is in many countries a registered trade mark of Innovia Films Ltd based in Wigton, Cumbria, United Kingdom.
The top plate of the cello is made of spruce or pine because of their good sound radiating qualities. The sides and back plate are made of maple. The neck, pegbox and scroll are made of maple. A thin piece of ebony is glued to the top side of the neck to form the fingerboard.