Development of the Skull. 23 



brain are removed from the preparation, which is mounted in 

 turpentine, and shows the vascularity of the developing bone. 



B. C. 1. N. 68. 



2. 25. Development of Skull. — Skull of a foetus, between 

 the fifth and sixth months — injected with vermilion and in 

 spirit. 



The preparation exhibits a shrivelling of the membrane, 

 which brings out more strongly the bone which has been 

 formed. B. C. 1. N. 67. 



2. 26. Development of Frontal Bone. — Two halves of the 



frontal bone of a foetus, about the second month — dried — showing 

 the development of the supraciliary ridges. B. C. 1. N. 60. 



2. 27. Development of Frontal Bone. — Two halves of the 

 frontal bone of a foetus, between the third and fourth month — 

 dried — showing the development of the frontal eminences and 

 supraciliary ridges. B. C. 1. N. 61. 



2. 28. Development of Frontal Bone.— Eight half of the 



frontal bone of a foetus, between the fourth and fifth month — 

 dried — showing the development of the frontal eminence, 

 supraciliary ridges, and orbital plate. B. C. 1. N. 62. 



2. 29. Development of Parietal Bones. — Parietal bones of a 



foetus about the second month, showing the centres of ossifi- 

 cation. B. C. 1. N. 59. 



2. 30. Development of Parietal Bones. — Parietal bones of a 



