The Intra-membranous bones develop from sheet-like masses of connective tissue unlike the Endochondral bones which develop from masses of hyaline cartilage with shapes similar to the future bone structures.
EXPLANATION:
Osteoblast cells develop due to the enlargement and differentiation of the primitive connective tissue.
This produces the spongy bone tissue in all directions. The outer layer of cells of the developing bone forms the periosteum which develops into connective tissues encircling the developing diaphysis.
This is followed by the formation of the primary ossification center followed by the secondary ossification centers resulting in the formation of the spongy bone.
