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tail being the longest and strongest on the body. Those which form the 
“foot locks” are peculiar to the horse, and vary in length and coarseness 
with the breed of the animal. When hair is fine and long and wavy, it forms 
wool; and when straight and rigid, as in the , /pig, it is known as bristles 
(Chauveau). 
' The sweat glands are very numerous over the surface of the body. 
They consist of small lobular masses formed of a coil of a gland tube 
surrounded by little blood vessels, and embedded in fatty tissue in or 
beneath the derma. From the coil passes a duct, which opens on the 
surface of the skin. According to Erasmus Wilson, there are as many as 
3,528 glands on each square inch of the palm of the hand of a man, while on 
the neck and back they only amount to 417. The total number of these 
glands in the human being is estimated at nearly two and a half millions. 
MANGE. 
AYTER these few preliminary remarks, we may at once proceed with the 
consideration of the’ symptoms and treatment of the various maladies of 
the skin of the horse. We shall first devote our attention to the parasitic 
‘diseases. These fall into two main groups, viz., those due to animal parasites, 
and those due to vegetable parasites belonging to the order of the fungi, 
such as the various kinds of ringworms. 
Mange or scab is an affection of the skin, decidedly contagious, caused 
by the presence of little creatures belonging to the same order as the 
mites. These little animals are of three varieties in the horse, 
but do not differ very much in appearance or size. The “scab” acari of 
slightly differing kinds infest man and all the domesticated animals. These 
parasites are said to live on the fluid, which is effused from the blood, owing 
‘to the irritation their presence sets up. 
The first kind which infests the horse, termed dermatodectes equi, of 
which we append a drawing, is the kind most frequently met with in England. 
This creature causes the formation of little elevations on the skin, in the 
upper part of which. the contents soon become liquid and burst, and 
afterwards becoming drier, form crusts or scabs. These little elevations or 
pimples, which are about an %th of an inch in height, are especially 
numerous on the upper part of the neck and root of the tail. Ifa few crusts 
“be taken off, placed on a white surface, and exposed to the heat of the sun, 
the parasites may easily be discerned with a small magnifying glass. The 
‘itching which is set up by these creatures is of an intense character. They 
deposit a secretion of great acridity, and by their long mandibles or jaws, 
they cause serious alterations in the skin, which is rendered bare, wrinkled, 
and bleeding, especially around the mane. The disease occasioned by them 
is more amenable to treatment, and spreads much more slowly than that 
produced by the second variety. The greater facility with which these 
creatures can be killed by the application of ointments, is no doubt due to the 
fact that they}do not burrow into the skin, but merely conceal themselves 
under and among the scabs. The dermatodectes live in colonies. 
