POSTERIOR MEMBER. 297 



volume that there appears, against the first phalanx, in the fold of the pastern 

 and on each side, the outline of two other tumors, always much smaller, whose 

 fluctuations are transmitted to the preceding. We have seen that these are the 

 points of the synovial membrane which are only feebly supported. 



Tendinous windgalls, formed within the great sesamoid sheath, are more 

 voluminous and ascend higher than the articular, behind which they are located. 

 Their exact position is the space comprised on each side between the suspensory 

 ligament and the tendons ; it is the point which corresponds to the superior, culs- 

 de-sac of the sheath in question. Below the fetlock there are two other smaller 

 tumors, in the fold of the pastern and along the latter border of the flexor 

 tendons ; they communicate with the superior, but are only visible in a state of 

 extreme dilatation of the sheath. 



The parietes of windgalls in time become thickened, indurated, and ossified. 

 The accumulation of a large quantity of synovia in their interior renders the 

 movements less easy, and occasions painful pressure upon the surrounding 

 tissues; and, in consequence, the articulation itself becomes deviated from its 

 normal direction owing to the mechanical restraint which it experiences and the 

 pain which it causes during station. 



The tendinous cords, relieving themselves instinctively, so to speak, from 

 their habitual tension, retract and tend to produce, little by little, a more or less 

 complete eifacement of the angle of the fetlock, a complication always grave by 

 reason of the vicious axis of the members which it occasions, knuckling. It is 

 then that the articular extremities, deprived of their apparatus of dispersion, 

 manifest the violence of the concussions which they experience during locomo- 

 tion by the appearance of osseous formations upon their periphery. The exos- 

 toses, whose formation is excited under the influence of these causes on the 

 anterior and the lateral faces of the fetlock, have received the name osselets. 



Generally speaking, the chronic diseases of the region, which we have 

 enumerated, are compatible with the normal function of the joint. But the hard 

 indurations of the tissues and the formation of osseous vegetations around the 

 articular margins produce a certain restraint of the movements. In spite of the 

 variable stiffness of the members, the animal is still utilizable. A decided lame- 

 ness, save in exceptional cases, appears only after a long time, when, for example, 

 the synovial membranes are very distended and the articular surfaces notably 

 altered. 



H. The Footlock and the Ergot. 



The footlock is a tuft of hairs situated behind the fetlock, around 

 the ergot. Properly speaking, it merits but little attention when a 

 horse is examined for soundness. It is small and formed of hairs of 

 fine texture in the finer races, while in the common races, whose pilous 

 system at the inferior part of the member is, in general, thick, coarse, 

 and very extensive, especially if the subjects inhabit low and damp 

 localities, it presents the opposite characters. It is not rare to see, in 

 these, the hairs of the footlock touch the soil and often ascend to the 

 posterior part of the knee. 



Many horse-merchants, in doing up the hairs, do not fail to cut the 



