268 Diseases of Bone. 



this piece to the rest of the bone. The bare patch has been 

 surrounded by vascular granulations, which have formed a 

 trench round it. It has thus evidently been necrotic, and in 

 process of separation. Beneath the bare piece there has been a 

 small abscess in the cancellated tissue. G. C. 1052. 



6. 162. Invasion of the Tibia by an Ulcer of the Leg*.— 



Section of portion of the previous specimen — macerated, to 

 illustrate the above. 



During maceration the bone was accidentally broken, and 

 has been wired together. 



The surface of the bare, necrotic piece of bone is porous. 

 The groove surrounding it is well shown. Beyond the groove 

 the very porous character of the bone, which during life was 

 covered^by granulation tissue, should be noted. This part merges 

 off above into new periosteal bone growth. G. C. 1&52. 



h. Where the chief changes are in the form of rarefaction. 



6. 163. Rarefaction of the Ulna after Compound Fracture. 



— Upper end of a left ulna — macerated, illustrating the above. 



The lower end of the fragment is very irregular,, and is 

 partially absorbed. The surface is covered irregularly with 

 periosteal new bone, while at places on the front the interior is 

 seen to be rarefied and absorbed. This has probably been the 

 result of a bad compound fracture. B. C. i. 5. M. 96. 



6. 164. Rarefaction and Necrosis of Femur after Ampu- 

 tation. — Portion of a femur, removed from a stump — macerated, 



to illustrate the above. 



One portion of it is dead, and has been in process of 

 separation. The rest is opened out and irregular, with some 

 periosteal new bone on the surface. The rarefactive change, if 

 anything, preponderates. F. P. C. 552. 



Presented by Professor James Russell. 



