Slide 96 - Trachea.  Sections of cartilagenous rings show groups of chondrocytes lying within hollow lacunae surrounded by matrix.  The matrix is often more basophilic (blue) near the cells.  Why?  Along the edge of the cartilage note the pink, dense collagenous perichondrium, with parallel rows of fibroblasts.  Cartilage is formed at the point of junction, as undifferentiated connective tissue cells (which look very much like fibroblasts) now become chondrobasts and lay down matrix substance and thus become confined as chondrocytes in lacunae.  Note the progressive changes in shape and size of these cells as you move toward the larger cells in the center of the cartilage.  Remember that fine collagenous and elastic fibers are running throughout the matrix but are not visible because of their similar refractive index to the intercellular matrix.