95 



Mr. Gamgee thinks " the most favorable for the development of 

 horses' feet," and therefore condemns the frequent use of water 

 and other dressings to those organs. 



VARIETIES AND EFFECTS OF CONTRACTION. 



Whether active contraction takes place at the upper or the 

 lower circumferent margins first will depend upon circum- 

 stances ; and whether contraction precedes expansion, will also 

 depend upon other active causes; but I have always found that 

 if one margin be expanded, the other is contracted. For ex- 

 ample, when coarctation or contraction of the upper circum- 

 ferent margin of the wall takes place, there is a corresponding 

 enlargement of the area of the lower one, giving the bell-shaped 

 form of foot. No ''atrophy'* can be implied in this condition. 

 It is simply an alteration of the external form, induced by ex- 

 traneous influences, gaining as much in one direction as it loses 

 in another. I regard it as a stricture or contraction of the hoof, 

 and when it is the cause of lameness, a removal of the stricture 

 removes the lameness. How this stricture can be removed will 

 be shown by and by. It is not an unfrequent source of lame- 

 ness, and in general it is easily removed, leaving the animal 

 perfectly sound in action. Reverse these conditions, and we 

 have the most frequent cause of lameness, and, moreover, is 



THE INVARIABLE CAUSE OF QUARTER-CRACKS. 



Let the lower margin of the wall co-arct, or close in preter- 

 naturally at the quarters, and there will be a corresponding 

 enlargement of area at the upper margin. The coronary liga- 

 ment receives an undue amount of pressure, and quarter-crack 

 is the very common result. One of the most common causes 

 of this falling in or wiring in of the quarters is " cleaning out 

 the heels " whenever the horse is shod, and exposing the soft ' 

 parts to the drying, and therefore contracting, influences of the 

 atmosphere. Occasionally there is lameness when the crack 

 starts; sometimes there is none. There is obviously here an 

 outward pressure of the internal tissues, which are not permit- 



