ANATOMY AND PHYSIOXOGY OF THE HORSE^S FOOT. 463 
exhibit the nucleus they contain. Soon, however, they 
become greatly elongated and fusiform, a feature which is all 
the more marked as we examine them towards the termina- 
tion or free margin of the lamina. 
On making a vertical section of the wall and horn leaf, so 
as to obtain a side view of the latter, this horizontal dis- 
position of the cells is yet more apparent in the striated 
aspect the lamina offers, and which gives it somewhat the 
appearance of conjunctival tissue. Treated with potash, this 
arrangement is made manifest (fig. 17). We see the long, 
fusiform corpuscles lying closely, one above another, destitute 
of fibres, and terminating rather uniformly at the edge of the 
leaf ; so elongated and narrow are they from every point of 
view, that they present nearly the same shape in a vertical 
as they do in a horizontal section. A peculiarity in their 
arrangement consists in their leaving the fibrous texture of 
the wall at a marked angle, inclining downwards in a plane 
nearly, if not quite, parallel with the lowest face of the 
coronary cushion. 
If the horn of the lamina has any tendency to a dark 
colour, pigment- granules will be found disseminated among 
the fusiform-like cells. 
This horizontal stratification of the cells of the keraphyl- 
lous tissue, together with the absence of intersecting con- 
tinuous fibres,* as in the wall, accounts for the tendency of 
Fig. 17— Lateral view of lamina (horny), showing horizontal stratified dis- 
position of fusiform cells, after boiling in caustic potash. Magnified 
350 diameters, a. Free margin. 
the laminae to split in the direction of the strata when they 
have lost their moisture. I have often remarked that a dried 
lamina bears a close resemblance in some of its characters to 
the dermo-skeleton or cutaneous covering of the Coleoptera 
* In one horny lamina I examined I found a fibre or tube in the middle 
of its substance, proceeding from its upper to its lower extremity. This 
would appear, however, to be a very exceptional circumstance. 
