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comes fainter towards the free margin of the nail, but which deepens 

 considerably where the nail becomes detached from the integument. 

 When the matrix is fully injected and the nail removed (see PI. 

 22, fig. 1), the part corresponding to the lunula presents several 

 rows of convoluted capillaries : the individual convolutions have diffe- 

 rent degrees of complexity, from a simple loop a little twisted around 

 itself, to a complex tuft of vessels. These rows have their direction 

 from above to below, they are all slightly curved, being concave to- 

 wards the median line of each nail, and the most external ones are 

 nearly parallel with its lateral margins ; (see PI. 23, fig. 7). These, 

 being the vessels which secrete the horny part of the nail, may be 

 called the horn-vessels. Superiorly these vessels are separated from 

 the rich plexus on the fold of integument which overhangs the nail, 

 by a fibrous and almost non-vascular groove, in which the free border 

 of the nail was lodged, and where the cuticle covering its root termi- 

 nates. A few vessels, however, pass across this groove from the horn- 

 vessels to the plexus just mentioned. Inferiorly the horn-vessels 

 communicate with quite a different arrangement of capillaries, which 

 run in a more straight course, and are much more crowded together 

 than the horn-vessels. These vessels run nearly parallel with one 

 another, in a direction from behind forwards, and being very near to- 

 gether render this the most vascular part of the matrix, and produce 

 that redness immediately below the lunula upon which the form and 

 degree of distinctness of its lower border is dependent. Just below 

 these vessels the surface of the matrix begins to be raised into nume- 

 rous plications or folds, passing directly forwards, and increasing in 

 depth as they approach the free extremity of the nail, where they be- 

 come continuous with the raised lines observable on the ends of the 

 fingers. These plicae consist each of a fold of basement membrane, 

 enclosing a series of loops of vessels. At first these loops are small 

 and simple, but they become larger and more complex as they ad- 

 vance towards the end of the finger, where they are continued from 

 the ridges of the matrix of the nail into those of the skin of the finger, 

 in which they are generally very complex. When the nails are in 

 situ, these ridges are received into corresponding grooves in their 

 inferior surface. Near the part of the matrix where the plicae com- 

 mence, several distinct circular or oval openings are sometimes seen 

 passing for some depth beyond the surface, and appearing like follicles 

 or lacunae ; (see PI. 23, fig. 7). These are frequently closed by the 

 apposition of the adjacent plicae, and thus their presence is rendered 

 doubtful, but they can be seen very distinctly either when some of the 



