The Slrudare of the Horse'ts Foot and Princijiles of Shoeing. 655 
When the hoof is taken off by the aid of heat, or by soaking 
for a time in water, the internal foot is displayed, and also the in- 
side of the horny box ; and the drawings in Plates 3 and 7 (pages 
662 and 666) show these parts after separation. The points for 
special notice are the very perfect fitting of the internal foot to 
the inside of the hoof. The coronary band (Plate 7, 1-3) of 
the one rests in the hollow in the upper part of the hoof 
(Plate 3, d), the folds of membrane (lamince) of the internal 
foot (Plate 7 (2) ) are lodged between the horny folds (lamiiue) 
of the inside of the hoof (Plate 3, a), and the sole of the internal 
foot, with the frog and the bars, find their exact counterparts in 
the inside of the hoof which thev form for their own coverinsr 
and protection. See Plate 8 (page 667), which shows the bottom 
of the foot : (1) coronary band continuing to sensitive frog (4) ; 
sensitiv^e lamina (2) continuing to bars (5) ; sensitive sole (3). 
After the hoof is off there is nothing in the way of the knife, 
which may now be used to take off the membrane which secretes 
the horn. The observer will find that the tissues beneath are 
bone, fibrous structure, fat, and cartilage. The bones actually 
inside the hoof are the pedal bone and the navicular bone, both 
of which are shown in Plate 9, figures A, B. To the pedal or 
coffin bone are fixed two wings of cartilage (2, 3), also seen in 
fig. A, and in the space between the cartilages is a mass of fibre 
and fat, making together an elastic pad which Coleman called 
the " fatty frog." 
It will be noticed that the pedal bone is a very dense 
structure, like ivoiy in hardness, and also that there are many 
canals passing through it in various directions for the passage 
of blood-vessels to supply the secreting membrane with blood. 
Branches of nerves are also very numerous, and the membrane 
of the internal foot is therefore correctly described as a highlv 
vascular and sensitive structure. 
The navicular bone (Plate 9, b) is known as the seat of the 
navicular disease, which is a common cause of serious and often 
incurable lameness in the foi'efeet. It is also remarkable for the 
extent of its joint surfaces compared with the size of the bone. 
Its upper surface forms part of the coffin joint with the short 
pastern. In front (2) it joins the pedal bone, and at the back 
(1) it forms a joint with the main fiexor tendon, which passes 
over it to be fixed to the bottom of the pedal bone. This is 
the joint in which navicular disease occurs. 
Functions of toe Foot. 
After seeing all the parts which form the foot of the horse 
the inquirer will begin to speculate about the use of each, and 
will most likely do what has been done before, viz. invent clever 
