22 Develoj)ment of the Bones. 



2. 19, Development of Skeleton, — Skeleton of human fcetus 

 about the fourth month — dried — showing the amount of bone 

 laid down at this period. The sockets of the teeth are now 

 perceptible. B. C. 1. K 87. 



2. 20. Development of Skeleton,— Skeleton— in spirit— of 



human foetus, about fifth month. The periosteum is left on 

 the bones, and the cartilaginous ends have the future shape 

 of the bones. 



The relative proportion of bone to cartilage and membrane 

 is not easily seen in this method of preparation. 



B. C. L N. 88. 



2. 21. Development of Skeleton. — Skeleton of a foetus, about the 

 fifth month — macerated and mounted on cardboard in separate 

 pieces — showing the relative amount of bone laid down at this 

 period. The right tibia and the bones of both feet are wanting. 



G. C. 3548. 



2. 22. Development of Skeleton. — Skeleton of human foetu& 

 about the sixth month — dried — showing the amount of bone 

 laid down at this period. B. C. 1. N. 89. 



2. 23. Development of Skull.— Skull of a foetus, about the fifth 

 nionth (brain and soft parts removed) — rendered transparent by 

 being mounted in turpentine, to show the development of 

 bones in the membrane. B. C. 1. N^. 66. 



2. 24. Development of Skull. — Skull of a foetus, probably 

 between the sixth and seventh months. The soft parts and 



