THE APPENDAGES OF THE SKIN. 



905 



The hairs of the tail are the longest and strongest in the body. These par- 

 ticular hairs also grow on the posterior aspect of the limbs, generally from 

 about the knees and hocks to the hoofs ; at the sesamoid bones they constitute 

 a long tuft— the fetlork—\\h\ch surrounds the horny growth named the " ergot." 

 These "foot-locks" are peculiar to the Horse, and vary in length and coarseness 

 with the breed of the animal.) 



When the hair is fine, long, and wavy, it forms wool .• and when straight and 

 rigid, as in the Pig, it is known as bristles. 



In the Ass and Mule, the forelock and mane are rudimentary or absent, 

 and the hair of the tail is 



limited to a small tuft at the F»g- 48". 



extremity of the organ in the 

 former animal ; while in the 

 latter it is much less abiindant 

 than in the Horse. 



In the Ox, these liairs 

 are not present, except at the 

 extremity of the tail, as with 



the Ass. 



There are no other animals 



which have other hair than 



that composing the coat. 

 (The oixlinary hair of the 



coat is soft and elastic, in- 

 clined in particular directions, 



and varies in length not only 



according to the regions of 



the body on which it grows, 



but also according to the 



season or climate. In the 



Horse, the direction of the 



hair of the coat gives rise to 



curiously formed waves, lines, 



and circles, the most constant 



of which is on the forehead. 

 In the Cow, the hair is 



frizzly on the forehead ; on 



the posterior part of the thighs 



it has a particular direction, 



while on the outer side it passes downwards, and from the posteric part of the 



mammjB it ascends as high as the vulva ; this characteristic disposition forms 



what the French have termed erussons, by which some have pretended to recognize 



the lactiferous qualities of the animal. 



In the Sheep, real hair — not wool — is found on the lower part of the face, 



and the extremities of the limbs. 



In the Goat, the hairs of the beard are veiy long, and compose a distinc- 

 tive tuft ; this animal has also a fine crisp duvet or down beneath the ordinary hair. 

 In the Pig, the bristles are very strong in the region of the back ; in old 



animals they are usually bi- or trifurcated at their free extremity ; there also 



exists a fine soft hair on this animal. It has no tentacular hairs. 



hair-folu:le. 

 1, External dermic layer ■ f tlie follicle; 2, internal dormic 

 layer; 3, amorphous linin'- of iSe follicle; 4, external 

 epidermic layer; 6, hair-bulb; 7. vascular papilla; 8, 

 cells of the medullary substance. 



