780 



DISEASES OF THE POLL. 



Fig. 563— Section of the Neck on a Level with the Poll 

 p.— The skin, to.— Lardaceous connective tissue on the top of cervical ligament, 

 gc— Superior extremity of the great complexus and small oblique muscle of the head. 

 Ic— Ligament nuchee. dp.— Posterior straight muscles of the head, lao.— Atloido- 

 occipital ligament. Is.— Superior part of the atlas. sm.— Rachidian dura mater. 

 m.— Spinal marrow, ta.— Adipose tissue of the rachidian canal, a. — Atlas, ph. — 

 Pharynx, go.— Section of the great oblique muscle of the head, ao.— Section of odon- 

 toid process of the axis, p.— Parotid gland, sm.— Sub-maxillary gland, da.— Anterior 

 straight of the head, ce.— (Esophagus. 



the head, the great oblique^ and under them, the posterior straight 

 muscles of the head; a serous sac, assisting the ghding of the 

 cord of the Hgamentum nuchse over the atlas, which is very small 

 in young animals, assumes larges dimensions in old subjects ; and, 

 finally, a skeleton of the region, the atlas, the axis and the occi- 

 pito-atloid and atloido-axoid articulations. Two large arteries are 

 distributed throughout the locality, the occipito-muscular and the 

 atloido-muscular. 



The causes in which diseases of the poll originate are numer- 

 ous. Among them may be mentioned first, bruises, from blows 

 given with the handle of a whij), or of a fork; contusions and 

 continued frictions against hard substances, as the manger; the 

 pressure and rubbing of the parts of the harness (the bridle, etc.), 

 which pass over that region; the repeated rubbing which the ani- 

 mal inflicts upon himself when he is afi'ected with parasitic cuta- 

 neous disease; the blows which he receives when in tossing his 

 head, he brings it in contact with the ceiling of his stable, when 

 this is too low, and he has formed the habit of pulling back on 

 the halter ; the spreading of diseases of the neck by the extension 

 of the necrosis of the cord of the cervical ligament, all these are 



