Epiphysis and diaphysis (40X)

In the epiphysis (diaphysis is the name of the middle part of the long bone, epiphysis the end part) you can see a secondary ossification center. Other epiphyses haven't reached this stage of development yet. In the epiphyses, there are many chondrocytes engulfed in cartilage. 

In the diaphysis, the growth of the bone has matured. You can see quite a few spicules of bone and bone marrow, all surrounded by cortical bone.