CHAP. V.] REPARATION OF BONE. 125 



sional, as it is gradually absorbed during the succeeding months, 

 while the permanent callus is being slowly deposited between the 

 contiguous surfaces of the compact tissue. It would appear that 

 new bone is formed more exuberantly in the situations of the provi- 

 sional callus because of their greater vascularity ; just as we may 

 suppose the function of ordinary nutrition to be more active in 

 those parts, than in the compact tissue of the bone. The perma- 

 nent callus has all the characters of true bone. 



When the reparative process in bone is interfered with, either by 

 mal-apposition of the fragments, or by constitutional fault, a spuri- 

 ous union may occur by the medium of a ligamentous substance, or 

 even a diarthrodial joint may be formed at the seat of fracture. 

 The ends of the bones become altered in form, and adapted to one 

 another ; a kind of false capsular ligament is developed, and some- 

 times even an imperfect cartilage, and a lining membrane furnish- 

 ing a lubricating fluid. 



The following works may be consulted on Bone : The systems of General 

 Anatomy already quoted (p. 87) ; Meckel, Anat. Generate Descript. et Patholog., 

 tom.i. ; Dr. Bostock's Physiology, where will be found an excellent and learned 

 summary of the observations of preceding physiologists on the structure and 

 growth of bone ; Mr. Paget's paper on the influence of Madder on the Bones 

 of growing Animals, Lond. Med. Gazette, vol. xxv. : Deutsch, de penitiori 

 Ossium structure, observationes ; 1834: Miescher, de inflammatione Ossium 

 eorumque anatome generali ; 1836 : Miiller's Physiology by Baly, vol. i. M. 

 Flourens has lately published a handsome volume on the growth of bone, 

 illustrated with figures. 



