895 



5811. The proximal phalanx of the great toe, longitudinally bisected. 



Prepared in 1851. 



5812. The distal phalanx of the great toe, longitudinally bisected. 



A medullary cavity is established in each of these bones. 



Prepared in 1851. 



5813. The metatarsal of the second toe, longitudinally bisected. Prepared in 1851. 



The following specimens, to No. 5832 inclusive, illustrate the osteogeny and progressive 

 growth of the Human skeleton : 



5814. The skeleton of an embryo of six weeks. 



It shows the early ossification of the haemal arches and appendages : this is exemplified in 

 the upper jaw, the lower jaw, the clavicles, the scapulae, the thoracic ribs and the innominata. 

 A single bony ray indicates respectively the humerus and femur: two rays represent the 

 radius and ulna in the arm, and the tibia and fibula in the leg, the two latter being of equal 

 thickness. Ossification has commenced in the occipital and frontal spines, but the neural 

 arches of these and of the other vertebral segments are unossified. 



This specimen was originally part of the Sloanian Museum. 



Mm. Brit. 



5815. A Foetal skeleton, one inch and a half in height. Mus. Heaviside . 



5816. A Foetal skeleton of two inches and a half in height. 



It shows partial ossification of the metacarpals, of the metatarsals, and of the proximal and 

 distal phalanges. The neurapophyses of the cervical vertebrae are, also, now ossified. 



Hunterian. 



5817. A Foetal skeleton, a little further advanced. Mm. Heaviside. 



5818. A Foetal skeleton, four inches in height. 



The neurapophyses of the dorsal and lumbar vertebrae have begun to be ossified, and the 

 middle phalanges of the fingers of the hand. 



Mus. Heaviside. 



5819. A Foetal skeleton, four inches and a half in height. Mus. Heaviside. 



5820. A Fcetal skeleton, five inches and a half in height. 



A centre of ossification is established in the body of each of the trunk-vertebrse. 



Mus. Heamside. 



