The Foot. 



367 



coronary edge of the foot at the moment of the greatest 

 weight, and describes it as an elastic ring. Dr. Macdonald,* 

 in this country, who has devoted attention to the vascular 

 mechanism of the horse's foot, considers that the swelling 

 up of the coronary cushion can only be regarded in the 



Fig. 48.— Diagrams illustrating the Expansion of the Foot. 



In the top figure the solid outline indicates the position of the foot at 

 rest : the dotted outline shows the retreat of the coronet, and 

 descent of the heels under the influence of the body weight ; the 

 shaded portion of the wall indicates the area of expansion. The 

 two lower figures are after Lungwitz : the left-hand one supposes 

 the observer to be looking down on to the foot ; the dotted outline 

 indicates the retreat of the coronet and descent of the heels ; the 

 dotted outline of the right-hand figure indicates the expansion of 

 the wall. 



light of a powerful hydraulic ligament, which supports the 

 joint under the immense strain to which it is exposed. 

 The value or existence cf this hydraulic support has yet 

 to be demonstrated. 



Lateral Cartilages. — We have dealt with certain functions 

 * Veterinary Record, No. 145, 1892. 



