Slide 21 Image 3/3
In the zone of ossification the lightly basophilic calcified cartilage matrix is removed by clastic activity of osteoclasts or chondroclasts. On these remnants of cartilage, ossification occurs by osteoblasts as they lay down pink-staining bone matrix on the residual core of calcified cartilage. Entrapped osteoblasts now become osteocytes.