558 Veterinary-Captain Frederick Smith [May 3, 



each lamina, both horny and sensitive, possesses secondary laminae or 

 lamellae ; of these there are about 150 to each primary lamina, so 

 that we may say the union between the sensitive and insensitive wall 

 is brought about by the dovetailing of 1000 primary and 150,000 

 secondary laminae. 



Here is a model of a single lamina 450 times larger than normal. 

 The structure rather reminds one of a fern leaf or feather, the stem 

 being the primary lamina, and the lateral projections the secondary 

 leaves. 



So much for the slinging apparatus. If time permitted I could tell 

 you much more of interest about it ; and the undoubted evidence we 

 possess that by it, and it alone, is the enormous weight of a horse's 

 body solely supported. 



We have one more point to discuss in connection with the laminae, 

 and that is the increase in the surface which they afford to the foot. 

 The sinrplest method of explaining my meaning is to take the common- 

 place example of a book consisting say of 500 pages, which when 

 bound in the ordinary manner is easily compressed into a body having 

 a small surface, yet if each of the 500 pages be removed and placed 

 side by side the area they cover would be considerable. Much 

 the same arrangement exists in the foot. By the folding up of horny 

 and sensitive material a very large surface is disposed within a very 

 small circumference, and careful measurements of the primary and 

 secondary laminae have led to the conclusion that the surface thus 

 contained within each foot of the horse is not less than eight to ten 

 square feet. 



The next part of the foot to receive attention is the sole. This, as 

 may be seen from the model and diagrams, is concave in shape towards 

 the ground, which is evidence, if any were required, that it is not 

 intended to support the horse's weight ; that margin of it, however, 

 in contact with the wall is doubtless capable of sustaining pressure. 



The function of the sole is to save the sensitive parts situated 

 above it from injury, and that it is eminently qualified for this purpose 

 is evident to any one who has witnessed the intense lameness which 

 arises from a stone getting wedged in the foot. 



The sole grows from the sensitive sole, which may be seen in the 

 diagram to be scarlet in colour and covered with numerous projections, 

 or papillae, which fit into minute holes on the upper surface of the 

 horny sole. 



A peculiarity in the horn of the sole is the fact that it only 

 grows a certain thickness before it breaks off. The object of this 

 is, that as the sole over its general surface is not in contact with the 

 ground, it is exposed to little or no friction like that of the wall, 

 which in a state of nature is maintained of proper length by 

 the friction to which it is exposed. The sole is therefore shed on 

 attaining a certain thickness, but no shedding occurs until a new sole 

 of suitable thickness has been produced to take its place. 



One of the common evils of shoeing is cutting away the sole of 



