I nclude the bone marrow, lymph nodes, spleen, and thymus. Precursor cells in the bone marrow produce lymphocytes. B-lymphocytes (B-cells) mature in the bone marrow. T-lymphocytes (T-cells) mature in the thymus gland. Besides providing a home for lymphocytes (B-cells and T-cells), the ducts of the lymphatic system provide transportation for proteins, fats, and other substances in a medium called lymph.
A book that is made with a stiff paper cover and bound directly to the text block. Many paperback books are converted to hardcover books by mylar binding. Perfect bind
1 Block (rural Australia), a small agricultural landholding. 2  Block (district subdivision), administrative region in some South Asian countries. 3  City block, the smallest area that is surrounded by streets.  License block, a geographically defined area for the purpose of the extraction of natural resources.