740 



SOLIPEDA. 



compression, which would soon become de- 

 structive. If it were necessary to employ any 

 single epithet to express the real nature of 

 this kind of locomotive apparatus, Bracy Clark 

 suggests that the term Semifissipes, or half- 

 cloven foot, would be less objectionable, 

 though also not exactly true, on account of 

 the presence of the frog, which, added to the 

 entire hoof in front, seems to afford the most 

 essential character of this kind of foot. 



Fig. 514. 



Dissection of the superficial Parts of the Horse's 



1, General integument ; 2, fatty mass, forming 

 a cushion behind the great pastern joint ; 3, wall of 

 the hoof turned back, showing the vertically lamel- 

 lated horny processes projecting from its inner sur- 

 face ; 4, section of the wall of the hoof; 5, articulation 

 between the cannon bone and the great pastern ; 

 6, 6, 6, aponeurotic tissues ; 7, 7, tendon of the ex- 

 tensor longus digiti pedis. 8, 9, 10, the flexor ten- 

 dons of the foot ; 11, 12, 13, 14, 15, expansions of the 

 great anterior cartilage of the foot ; 16, the coronary 

 frog-band raised from the hoof; 17, the vascular or 

 sensitive hoof; 18, elastic cushion of the heels; 19, 

 20, 21, arteria plantaris; 22, 23, plantar veins; 25, 

 part of the coronary venous plexus raised from its 

 position ; 26, 27, 28, plantar nerves. 



Cartilages of the Toot. On removing the 

 hoof there are seen immediately beneath it 

 two large elastic cartilages ranging to a great 

 extent along both sides of the foot. Their 

 figure is almost too irregular for comparison ; 



but, when seen on a lateral view of the foot, 

 their shape may be said to resemble that of 

 a lozenge or of a pretty fully expanded fan, 

 fixed by its centre, which is very much thicker 

 and more solid than the other parts, in a deep 

 horizontal cavity or channel in the coffin bone 

 provided for its reception ; from this central 

 point of insertion the anterior portion of it, 

 passing forward, nearly meets the cartilage of 

 the opposite side in front of the foot, the great 

 extensor tendon of the foot only separating 

 them, with which they are likewise connected, 

 and make a common surface. On its inside this 

 extremity of the cartilage takes a strong ad- 

 herence to the condyles of the coronary bone, 

 and so closely surrounds the joint betwixt the 

 latter and the coffin bone that the articulation 

 appears to be without any capsular ligament 

 at this part. The posterior portion of the 

 cartilage, ranging more largely and becoming 

 thinner as it expands itself backwards, growing 

 at the same time more elastic in its texture, is 

 gradually and inseparably mixed up towards the 

 hinder part of the foot with the skin and the 

 ligamentary elastic tissues that form the "upper 

 heels," and constitute the principal materials 

 for elasticity in these parts. Spreading also in 

 an upward direction to a considerable height 

 above the hoof, it terminates by a rounded, 

 thin, and irregular edge, which is inflected 

 inwards over the soft interior of the foot, to 

 which it forms a kind of roofing and defence. 



Next, this widely distributed cartilage may 

 be observed passing downwards, and surround- 

 ing on every side the rough and knotty ex- 

 tremities of the heels of the coffin bone, 

 entering and filling up its sinuosities, and 

 taking strong adherence to these processes ; 

 it then extends itself horizontally inwards, 

 passing over the horny sole and bar, and, 

 meeting the side of the sensitive frog, inti- 

 mately unites with it, forming one inseparable 

 mass, and together filling up the whole internal 

 area described by the sides of the coffin bone. 

 The upright or lateral portion of the cartilage 

 forms, with this horizontal process inwards, a 

 right angle, thus making together a hollow 

 space or receptacle at the back of the coffin 

 bone, that contains the spongy elastic stuffing 

 of the heels, together with the tendons, trunks 

 of bloodvessels, nerves c., passing through 

 this part to the sole of the foot. The upper 

 surface of the horizontal process of cartilage 

 is full of scabrous elevations and depressions 

 that defy dissection, among which there exists 

 a quantity of a gelatino-ligamentous material. 

 Beneath, or to the under surface of this hori- 

 zontal layer of cartilage, the sensitive sole 

 and bar are adherent ; and, in approaching the 

 frog, or centre of the foot, it loses its carti- 

 laginous nature, and becomes coriaceous, or 

 rather ligamento-coriaceous, in texture, agree- 

 ing in this with the internal frog. 



The horizontal portion or process of the 

 cartilage, named by veterinary writers the 

 "stratiform process," is of greater thickness 

 and substance than the other parts ; it is also 

 of a coarser grain and more elastic nature ; 

 both portions together communicate the gene- 



