BLOOD-VESSELS OP THE NECK. I57 



If only one of the depressor muscles were to act, the head would be bent 

 down, but it would likewise be turned towards that side. Then it will b& 

 easily seen that by this simple method of having the^muscles in pairs, pre 

 vision is made for every kind of motion, upwards, downwards, or on either 

 side, for which the animal can possibly have occasion. 



This is the proper place to speak of the mane, that long hair which covers 

 the crest of the neck, and adds so much to the beauty of the animal. It 

 sometimes grows to a considerable length. There is a horse in the king's 

 stables, the hair of whose mane is more than a yard in length ; and it is 

 said that a horse was once exhibited with a mane three or four yards 

 long. The mane is apt to become entangled, if it be not regularly 

 combed. The teeth of the comb should be large and sufficiently far apart. 

 There never can be occasion to pull the mane, as grooms are too much 

 accustomed to do, tugging it out in little parcels. It will then never lie 

 smooth. A "strong comb, with only two or three teeth in it, will keep it 

 sufficiently thin and smooth. 



THE BLOOD-VESSELS OF THE NECK. 



Running down the inner part of the neck are the principal blood-vessels 

 going to and returning from the head with the windpipe and gullet. 

 Our cut could not give a view of the arteries which carry the blood from 

 the heart to the head, because they are too deeply seated. The external 

 arteries ai'e the carotid, of which there are two. They ascend the neck on 

 either side, close to the windpipe, until they have reached the middle of 

 the neck, where they somewhat diverge, and lie more deeply ; they are 

 covered by the sterno-maxillaris muscle, which we have just described; 

 and are separated from the jugulars, by a small portion of muscular sub- 

 stance. Having reached the larynx, they divide into two branches, the 

 external and the internal ; the first goes to every part of the face and the 

 second to the brain. 



The vertebral arteries run through canals in the bones of the neck, 

 supplying the neighbouinng parts as they climb, and at length enter the 

 skull at the large hole in the occipital bone, and ramify on and supply 

 the brain. 



We can conceive few cases in which it would be either necessary or jus- 

 tifiable to bleed from an artery. Even in mad-staggers the bleeding is more 

 practicable, safer, and more effectual, from the jugular vein than from the 

 temporal or any other artery. If an artery be opened in the direction in 

 which it runs, there is sometimes very great difficulty in stopping the bleed- 

 ing ; it has even been necessary to tie the vessel in order to accomplish 

 this purpose. If the artery be cut across, its coats are so elastic that the 

 two ends are immediately drawn apart under the flesh on each side, and are 

 thereby closed ; and after the first gush of blood, no more can be obtained. 



THE VEINS OF THE NECK. 



The external veins which return the blood from the head to the heart 

 are the jugulars. The horse has but one on either side. The human 

 being and the ox have two. It is the principal vessel by which the blood 

 is conveyed from the head. The jugular is said to take its rise from the 

 >)ase of the skull ; it then descends, receiving other branches in its way 

 towards the angle of the jaw, and behind the parotid gland ; and emergmg 

 from that as seen at t, p. 150, and being united to a large branch from tho; 



