BLOOD-VESSELS OF THE NECK. 157 



If one only 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 be 

 easily seen that by this simple method of having the muscles in pairs, pro- 

 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 ani- 

 mal. 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 are 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, sup- 

 plying the neighbouring parts as they climb, and at length enter the scull 

 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 

 justifiable 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 

 bleeding ; 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 ob- 

 tained. 



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 base of the scull ; it then descends, receiving other branches in its 

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

 emerging from that, as seen at t, p. 120, and being united to a large 



