Calcification of the teeth begins at the seventeenth week of fœtal life.
The hyaline cartilage of the vertebral region forms a vertebral body in which calcification may to some extent take place.
Calcification of the media is found and is said to be preceded by hypertrophy of the middle coat.
When the calcification occurs in plates through the media, the well known pipe stem vessel is produced.
Occasionally hyaline degeneration or calcification of the new-formed tissue is seen.
Points of calcification occur in the cartilages and tendons in very chronic cases.
Cases have been reported of calcification of the arteries in infants and children.
Here the inflammatory process extends to the lateral cartilages, with a strong tendency to calcification.
As for the calcification of the two valves together, we have seen, under the last variety, how little important a character it is.
The illustration (Fig. 50) shows the progress of calcification and development of the temporary set of teeth.