40 



ANATOMY OF VERTEBRATES. 



number of subvertical lamellae, fig. 17, 3, with which interdigi- 

 tate corresponding lamellae, ib. 17, from the periosteum of the 

 ungual phalanx : the first are called the ' horny lamellae,' the 

 second the ■ vascular ' or ' sensitive lamellae.' At the interspace 

 between the inflected parts or prongs of the ' wall ' projects the 

 mass of elastic subcorneous tissue called by the French farriers 

 ' fourche,' and misnamed by the English ' frog.' In the horizontal 

 section of the hoof, fig. 16, in which a part, 2, is reflected back, the 



' frog,' 3, is seen to extend to the 

 centre of the sole : its exposed outer 

 surface is the hardest and most 

 horny ; but this tissue is not so thick 

 as some farriers, misapplying the 

 paring-knife, suppose: it gradually 

 passes into elastic tissue : it is im- 

 pressed at its middle part by the 

 * cleft of the frog,' and is reflected 

 upon the 'internal wall.' In fig. 

 16, 2, 6, is the section of the ' wall ; ' 



3, the upper surface of the ( frog ; ' 



4, 4, are the parts of the ' wall ' 

 called the ' heels ; ' 5, parts of the sole 

 called the 'bars;' 7— n indicate the 

 boundaries of the space lodging the 

 frog ; 12, are the ' vascular lamellae.' 

 The horny matter of the sole possesses 

 more elasticity than that of the wall : 

 the sole is slightly concave toward 

 the ground, abutting by its lower 

 circumference against the wall : it is 

 cleft to its centre by the triangular 

 space through which the frog pro- 

 jects. 



In fig. 17,1 is the skin reflected ; 

 2, soft elastic tissue, with oil, forming a cushion behind the me- 

 tacarpo-phalangial joint ; 3, ' wall ' of the hoof turned back, 

 showing the horny lamellae ; 4, section of front part of the ' wall ; ' 

 5, 6, ligamentous parts of metacarpo-phalangial joint ; 7, tendon 

 of common * extensor;' 8, 9, 10, those of the deep and superficial 

 flexors ; 15, expansion of the great anterior cartilage of the hoof; 

 16, the ' coronary frog-band ' reflected ; 17, the ' vascular lamellae; ' 

 is, elastic portion of the 'frog;' the 'coronary venous plexus' 

 is shown at ^5. 



Transverse section of the boof of the 

 Horse. nr\ 



