658 A MANUAL OF VETERINARY PHYSIOLOGY 



each leaf terminates in five or six papillae. The leaf is extremely 

 vascular — in fact, quite scarlet in colour — the effect over the who\ 

 mass of leaves being very striking in appearance. If the tissue be 

 examined microscopically, it is found that part of its substance is 

 devoted to leaf-formation, whilst the remainder is a sublaminal 

 tissue, the function of which is to secure the laminae firmly to the 

 wall of the pedal bone. This sublaminal tissue has been described 

 by Moeller* as consisting of two layers ; the one nearest the bone 

 is designated the stratum perio stale, and acts as the periosteum of the 



Fig. 223. — The Hoof removed, and the Vascular Wall seen from the 



Front. 



i, Groove between the skin and wall-secreting body from which the periople grows ; 

 2, the wall-secreting body : the rough surface is due to papillae and small 

 adherent fragments of horn ; 3, the beginning of the sensitive laminae ; 

 4, the laminae ; 5, their papillated ends. 



bone (Fig. 225A, b). Outside this is a layer of fibrous connective 

 tissue and elastic fibres, arranged in bundles, crossing and forming 

 networks ; this layer is extremely vascular, and has been designated 

 the stratum vasculosum. External to this layer are the laminae, 

 formed of elastic and connective-tissue fibres, as in the previous layer, 

 only the network is much finer. The laminae contain numerous 

 bloodvessels and nerves. 



The microscopical appearance of a transverse section of the vas- 

 cular laminae is shown in Fig. 225A, from Moeller. Each sensitive 

 lamina is not smooth, as its naked-eye appearance indicates, but 

 denticulated, each tooth-like depression representing secondary 

 * Veterinary Journal, vol. v., p. 1 14. 



