336 SKIN, COLOUR, AND HAIR. 



is the wall — is made up of dark and slate-coloured horn, 

 the foot is usually strong, and such as the farrier delights 

 to work upon. The chestnut-coloured horse has the worst 

 feet of any class of horse extant. The walls are weak 

 and brittle, and very often flat and shallow. Granted, 

 some chestnut-coloured horses' feet look very nice to 

 the eye, and show off to great advantage when newly 

 shod, but nevertheless, the fact remains that their feet 

 are weak in build and texture, and not the most suitable 

 for road purposes." 



The colour of the skin itself is either black, pink, or 

 it may be partly black and partly pink in patches. 



The black colour of dark skin is caused by the presence of black 

 pigment (melanin) which is deposited in the deeper layers of the 

 outer skin {epidermis). Melanin appears to be derived from the 

 colouring matter of the blood (hcEinoglobin), because the deposition 

 of melanin in various tissues is a characteristic of malarial fever. 

 Hemoglobin is contained in the red corpuscles of the blood, a large 

 number of which become destroyed by the microbes of malarial 

 fever during an attack of this disease, and consequently the blood, 

 in these cases, becomes loaded with free haemoglobin. There is no 

 pigment in pink (or white) skin. 



Although the large majority of grey and white horses 

 have black skins ; pink skin will invariably produce 

 white hair, and will secrete (at the coronets) white hoofs. 

 Black skin will form dark-coloured horn, even when the 

 coat is white. Although, as I have just said, white horses 

 may have black skins ; we shall find that the skin of white 

 markings (stars, blazes, reaches, snips, stockings, etc.) on 

 dark-coloured horses is, as a rule, pink. In fact, I venture 

 to say that the skin of white stockings is always pink, and 

 consequently the hoofs of these legs will be white ; provided 

 of course, that the white hair is continued down to the 

 coronet. In the East, we not infrequently see pink- 

 skinned horses, which, of course, are white, and which, 

 according to my experience, are much " softer " in constitu- 

 tion than animals with dark skins. This fact is, I think, 

 chiefly owing to the greater effect the rays of the sun have 



