Our understanding of the problems of bone development and growth draws on many fields of scientific endeavor in order to build up a complete philosophy of the subject. A purely anatomic and histologic approach, while extremely valuable and for many years our only method of attacking the subject, gave us but a very incomplete picture of the natural history of bone. Tissue cultures, when added to the already existing data furnished by ground and decalcified sections, carried forward our appreciation of this complex subject.
Now, more recently, we have been enabled to add to our previous information that gained by studies on the physical structure and chemical composition of bone, and are well on the way to a more comprehensive understanding of osseous tissue than we possessed before. On the basis of our newer knowledge, it becomes necessary to revise somewhat the older views of bone physiology and pathology.