JUGULAR LYMPH SACS AND CHANNELS — NECK OF PIG 61 



of the neck and the pharyngeal gland of the pig are represented 

 by groups of glands in the human being. The glands of the pos- 

 terior triangle of the neck in a new born are well shown in the 

 figure by Bartels, quoted above. 



In the adult pig the superficial cervical plexus becomes a group 

 of from twelve to eighteen glands lying along the external surface 

 of the sterno-cleido-mastoid muscle. They are of all sizes varying 

 from 1 by 2 cm. long to one very large gland measuring 2 by 3 

 cm. just behind the ear near the origin of the sterno-cleido-mastoid 

 muscle. This group of superficial glands clearly come from the 

 superficial cervical plexus and the vessels which grow from it. 

 The efferent vessels from the superficial glands show well in 

 Bartel's figure, that is those that run to the glands in the posterior 

 triangle. The development of the superficial plexus leads one to 

 expect that other efferent vessels follow the external jugular vein. 



From this study it is possible to obtain a clear idea of all the 

 lymph channels in the neck of the pig. From the apex of the 

 jugular lymph sac develops a large node in the posterior triangle 

 of the neck which receives the occipital, the suprascapular and 

 the superficial cervical lymphatics, that is to say practically 

 all of the superficial lyinphatics for the anterior part of the body. 

 The rest of the sac becomes the deep jugular lymph trunks and 

 lymph glands of which the most cerebral one is by far the largest. 

 The deep jugular glands drain the pharynx and Eustachian tube, 

 the nose and in part the vessels of the tongue and lower jaw. 

 The superficial cervical group of glands has the most complicated 

 development. This group comes not only from the apex of the 

 sac around the dorsal surface of the sterno-cleido-mastoid muscle 

 but from the sac stalk or deep jugular trunk by vessels which 

 follow the external jugular vein. It may also have a direct vessel 

 from the veins. The superficial cervical plexus drains the poste- 

 rior auricular region, the temporal, facial and cervical regions as 

 well as the thoracic wall and the skin of the arm. The deep or 

 axillary lymphatics of the arm have not yet been followed in the 



pig- 

 One of the most important points in this study is that there are 

 primary plexuses of lymphatics for each region, that these primary 



THE AMERICAN JOURNAL OF ANATOMY, VOL. U, NO 1 



