20 Development of Bone. 



2. 9. Cancellous Tissue in the Lower End of a Femur.— 



Vertical sections of the lower end of a right femur — macerated 

 and dried — to show the arrangement of the cancelli. 



W. C. F. U. 



PROCESS OF DEVELOPMENT IN GENERAL. 



2. 10. Ossification in Cartilag-e.— A portion of the cartilage 

 of a young elephant, beginning to ossify (apparently injected 

 with mercury to show the blood-vessels). B. C. 1. N, 18. • 



2. 11. Ossification at Knee Joint— Section of the bones form- 

 ing the knee-joint of an infant at birth — injected and in spirit — : 

 showing the process of ossification. 



The central nuclei of bone in the epiphysial cartilage of 

 the femur and tibia are well seen. The patella remains quite 

 cartilaginous. B. C. 1. iN". 23. 



2. 12. Ossification of the Lower End of Femur.— Sections 

 of the lower end of the femur of a child — injected with vermilion 

 and in spirit — to show the cartilage that remains between the 

 shaft and the epiphysis until the ossification is complete. 



The channels for blood-vessels are seen in the ossifying 

 cartilage. B. C. 1. K 28. 



2. 13. Ossification of Astragralus.— Right astragalus of a, 

 child — minutely injected and in spirit. 



The ossification is now complete, and the cartilage, which 

 is now only articular, has not been at all penetrated by the 

 injection. B. C. 1. K 26. 



