Organs of the Animal Body : their Forms mid Uses. 2d- 
together, would form a pipe 73J feet in length. If all the tubes 
of a man's skin were thus joined, a pipe of 28 miles long would 
be the result, according to calculations made by Sir Erasmus 
Wilson. 
Fig. 17. — Section of Horse's Skin. From Wing of the Nostril. 
E, cuticle ; D, true skin (derma) ; 1, horny layer of cuticle ; 2, cell structure above the vessels of 
the true skin ; 3, vascular layer ; 4, duct of a sweat gland ; 5, gland which excretes sweat ; 
6, hair follicles ; 7, sebaceous gland ; 8, internal sheath of hair follicle ; 9, bulb of the hair ; 
10, mass of fatty tissue. 
Uses of the Skin. — With the facts above stated in his mind, 
the farmer will lay aside the hide with something like a feeling 
of respect for a structure so complex and important ; and this 
feeling will be increased by the thought of the great work which 
the skin has to do. First, as a guard to the tissues beneath, keep- 
ing them from injury ; next, as a vast drain through which a great 
part of the waste of the body is poured out along with the sweat, 
which is always being given off, either as a vapour or a liquid, 
from the sweat-tubes, running off the skin sometimes in streams, 
or passing as a gas into the air without being seen ; in either 
case regulating, by the process of evaporation, the heat of the 
animal's body. Lastly, the skin and hair deserve a thought, as 
the structures which put the finish on the animal's form. The 
old saying that " beauty is but skin deep," would, perhaps, be 
keenly felt by a stock-owner who stood by the carcass of a 
prize ox after the hide had been removed. 
Muscle (Flesh). — The carcass deprived of the skin presents 
many points worthy of notice. A large part of the exposed sur- 
face is covered with red flesh, with fat here and there, and white 
glistening fibre : of these the red flesh is the most interesting. 
