FRAOTUBES. 303 



which the process is going forward of converting the cartilaginous 

 into the osseous form. 



The restorative process is sooner completed in the carnivorous than 

 in the herbivorous tribes. In the former the temporary callus may 

 attain sufficient fineness of consistency for the careful use of the limb 

 within four weeks, but with the latter a period of from six weeks to 

 two jnonths is not too long to allow before removing the supporting 

 apparatus from the limb. 



This, in general terms, represents the fact when the resources of 

 nature have not been thwarted by untoward accidents, such as a want 

 of vigor in the constitution of the patient or a lack of skill on the 

 part of the practitioner, and especially when, from any cause, the 

 bony fragments have not been kept in a state of perfect immobility 

 and the constant friction has prevented the osseous union of the two 

 portions. Failures and misfortunes are always more than possible, 

 and instead of a solid and practicable bony union the sequel of the 

 accident is sometimes a false joint, composed of mere flexible carti- 

 lage, a poor pseudarthrosis. The explanation of this appears to be 

 that, first, the sharp edges of the ends of the bone disappear by 

 becoming rounded at their extremities by friction and polishing 

 against each other. Then follows an exudation of a plastic nature 

 which becomes transformed into a cartilaginous layer of a rough 

 articular aspect. In this bony nuclei soon appear, and the lyniph 

 secreted between the segments thus transformed, instead of becoming 

 truly ossified, is changed into a sort of fibro-cartilaginous pouch, or 

 capsular sac, in which a somewhat albuminous secretion, or pseudo- 

 synovia, permits the movement to take place. Most commonly, how- 

 ever, in our animals, the union of the bony fragments is obtained 

 wholly through the medium of a layer of fibrous tissue, and it is 

 because the union has been accomplished by a ligamentous formation 

 only that motion becomes practicable. 



Prognosis. — The prognosis in a case of fracture in an animal is one 

 of the gravest vital import to the patient, and therefore of serious 

 pecuniary concern to his owner. The period has not long elapsed 

 when to have received such a hurt was quite equivalent to undergoing 

 a sentence of death for the suffering animal, and perhaps to-day a 

 similar verdict is pronounced in many cases in which the exercise 

 of a little mechanical ingenuity, with a due amount of careful ilurs- 

 ing, might secure a contrary result and insure the return of the 

 patient to his former condition of soundness and usefulness. 



Treatment. — Considered, per se, a fracture in an animal is in fact 

 no less amenable to treatment than the same description of injury 

 in any other living being. But the question of the propriety and 

 expediency of treatment is dependent upon certain specific points of 

 collateral consideration. 



