3 92 ANATOMY AND PHYSIOLOGY OP THE HORSE’S FOOT. 
whole fibre, and portions of two others, from the lower half 
of the wall, the relations of the fibre-cells to the interfibrous 
Fig. 15. — Transverse section of three horn-fibres from the wall of the hoof, 
lower margin; after boiling with caustic potash. Magnified 350 
diameters, a . Interfibrous cells, b. Fibre-cells. 
structure, which is found to he also cellular, is at once dis- 
tinguishable. While the cells composing the fibres are 
arranged in dense concentric layers around these in a vertical 
direction, the interfibrous cells are comparatively loosely 
placed, and in a horizontal manner ; so that in the hoof we 
have the epidermic or epithelial cells assuming two directions, 
those of the fibres proceeding in the same course as these, i.e. 
from above downwards, closely packed behind each other, 
and the interfibrous cells, polygonal in shape, laid in the 
contrary direction, i.e . horizontally, less densely agglome- 
rated, and without any particular regularity. 
In a transverse section of a fibre we can only perceive the 
edges of the cells ; but those lying between the fibres 
show their faces quite distinctly, their margins being more or 
less directed towards the sides of the fibre-cells. This 
arrangement is made still more manifest, perhaps, if we make 
a perpendicular section of a small portion of the wall. When 
carefully made and prepared for examination, this section is 
very interesting, and enables us to understand at once the 
