SHOEING. 



591 



leased. But it must be remembered that this arrangement 

 becomes feebler in proportion to its length ; that is to say, that 

 the tendons sustaining the three phalanges become more weighted 



a. Wall, with its 

 horntubes; b. b. 

 Horny laminae pro- 

 jecting from the 

 wall ; c. c. Horn- 

 tubes formed by 

 the terminal villi of 

 the vascular lami- 

 nae, the horn sur- 

 rounding them and 

 occupying the 

 spaces between the 

 horny laminae, con- 

 stituting the "white 

 line;" d. Horny 

 sole, with its tubes. 



be d 



FIG. 384. Horizontal section of the junction of the 

 wall with the sole of the hoof. 



and fatigued as the lever formed by these phalanges becomes 

 longer. 



B. The plantar cushion has duties indicated by its structure 

 and position ; it fulfills the office of a buffer on which shocks may 

 be spent and extinguished. When subjected to shocks or the 



a. Inner portion 

 of the wall with 

 the laminae aris- 

 ing from it ; b. 

 Vascular laminae ; 

 e. Horny laminae 

 of average length; 

 c'. c', Unusuall}" 

 short laminae ; c '. 

 c". Laminella on 

 the sides of the 

 horny lamime ; d. 

 Vascular laminae 

 passing between tf. 

 two horny ditto ; 

 d'. Vascular lami- 

 n a passing b e- 

 tween three 

 horny lamina); 

 d". Lateral lami- 

 nellce ; e, e. Arte- 

 ries of vascular 

 1 a m i n ;e which 

 have been i n- 

 jected. 



c' c" d" d' e 



FIG. 385. Horizontal section of the wall, and horny and 

 vascular laminae, to show the junction of the latter 

 and the laminelle. 



pressure of weight, it flattens and extends, to resume its form 

 when the pressure is removed ; but in its enlargement it presses on 

 the cartilages, which yield because of their flexibility and elasticity ? 

 and come back to their own shape immediately when the action of 

 the plantar cushion ceases. 



