G82 OPERATIONS ON THE FOOT., 



horny appearance, but softer, fills uj) the si^ace situated between 

 the walls and the keratogenous structure. This is the product of 

 the exudation of the inflamed podoj:»hyHous laminae, mixed with 

 the horny substance which they secrete normally. These laminae 

 are themselves hypertrophied, being sometimes one and two cen- 

 timeters in length and exceeding by four or five times their nor- 

 mal size. The keraphyllous laminae are also hypertrophied, a 

 condition which is evidently due, as resj)ects the podophyllous 

 tissue, to the increase of vital activity, resulting from the inflam- 

 matory condition of the tissue and to the infiltration by fibro- 

 plastic exudation, resulting from the inflammation. As to the 

 keraphyllous laminae, they rejDeat on the internal face of the wall, 

 in an inverse manner, the disposition of the secreting laminae of 

 the hoof between which they are formed and lodged. These, 

 however, as they increase in extent, unite at their base in the 

 whole of that portion which does not co-operate to theu' union 

 with the podophyllous bands, and then forms a compact mass 

 uniting most frequently with the internal face of the wall. Some- 

 times this mass of yellowish hoof occupies the whole space be- 

 tween the OS pedis and the wall, but, in some cases, it adheres 

 only to the wall, when it forms around the keratogenous tissue, a 

 new wall, also provided with keraphyllous laminae, and there is 

 formed between it and the normal wall that porous, brittle mass, 

 without homogeneity, which fills up the space, which constitutes 

 the seedy toe. The mass thrown between the wall and the os 

 pedis presses upon it ; the anterior face of the bone assumes a 

 vertical direction, and the os pedis presses toward the solar arch 

 on its anterior border at a point situated posterior to that where, 

 in normal feet, this border rests. Notwithstanding its resting 

 power, the wall gives to the effort of the mass interjDosed in front, 

 the form of the foot changes, and then results the change to the 

 oval in the contour of the foot. Under the influence of the dis- 

 placement of the phalanx, not only the flattening and afterward 

 the convexity of the sole and even its perforation results, but the 

 plantar cushion is itself pressed down and crushed between the 

 bone and the frog, which is then generally atrophied. A hoof of 

 new formation is often developed between the sole and the infe- 

 rior face of the phalanx, in order to prevent it from necessarily 

 sinking. This increases the pressure upon the bone and contrib- 

 utes to its atrophy and sometimes to its complete disintegration. 



