so 



FKACTURES AND DISEASta OF BOrriLa. 



joint having extensive motion, and that the /rachcred ends can dc 



kept at rest. 



An early consequence of fracture appears to be an exudation 



of 1^'mph, which is at first dimly granular, but becomes, at a 



later period, . ruddy, elastic, or moderately firm and succulent. 



It soon attains firmness, when it is called a callus. 



There are two methods according to which the calhis may 

 be placed. In one method the broken 

 ends or smaller fragments of bone 

 are completely enclosed in a new 

 material ; they are ensheathed or held 

 together by it, as two portions of a rod 

 might be by a ring fastened round them 

 both. 



The new material, in such a case, 

 surrounding the fracture is termed 

 " provisional," " external," or " en- 

 sheathing" callus. 



In the other method the new mate- 

 rial is only placed between those 

 parts of J:.he broken bone whose sur- 

 faces are opposed ; between these, it 

 is inlaid, filling the space that would 

 else exist between them, and uniting 

 them by being fixed to both (like 

 the process of gluing two pieces of 

 wood). Reparative material thus 

 placed has been called intermediate 

 callus. In either method, tliere is 

 usually some reparative material de- 

 posited in and near the medullary 

 tissue, and this is called interior 

 callus. 



In fractures that occur in the lower 

 animals, with the exception of those 

 Fio. 9.— Oblique fracture of found in the fixed bones, the en- 



the tibia, with external (ensheath- 71 • i 



ing) callus, marked a and 6. The sheathmg callus IS USUal. 



line extending from a indicates From the researches of HaUet, 



the seat of the fracture, the new i tt t^ 1. T> f 



deposit (callus) being purjKJsely Duhamcl, Hunter, Dupuytren, 1 agex;, 

 removed. ^^^j Stanley, we find that nature never 



