LYMPHATICS OF THE HEAD AND NECK. 499 



their progress upwards some of them have communication near the wrist 

 with the superficial lymphatics ; and some of them enter the glands which 

 lie by the side of the brachial artery near the bend of the elbow. They all 

 terminate in the glands of the axilla. 



The lymphatics of the chest consist of branches running under cover of 

 the pectoral muscles, and of subcutaneous vessels, twigs of which are con- 

 tinued from those on the abdominal wall as low as the umbilicus, decus- 

 sating with the vessels which converge to the inguinal glands. 



The superficial lymphatics of the back converge to the axillary glands from 

 its various regions ; from the neck over the surface of the trapezius 

 muscle, from the posterior part of the deltoid, and from the whole dorsal 

 and lumbar regions as low as the crest of the ilium ; the branches decus- 

 sating inferiorly with vessels leading to the inguinal glands, and likewise 

 crossing the middle line so as to decussate with branches of the opposite 

 side. (Mascagni, Tab. xxii., xxiii. , xxiv.) 



LYMPHATICS OF THE HEAD AND NECK. 



The lymphatic glands found on different parts of the head and face are 

 few and small : those in the neck, on the contrary, are comparatively very 

 large and numerous. 



The cervical glands are placed chiefly on the sides of the neck, and 

 are divisible into a superficial and a deep series. Of the former, some lie 

 beneath the base of the inferior maxillary bone ; the remainder, arranged 

 along the course of the external jugular vein, exist in greatest number in 

 the angular space behind the lower end of the sterno-mastoid muscle, where 

 that vein enters the subclavian vein : at this point the cervical glands 

 approach and are connected with the glands of the axilla. The deep 

 cervical glands are placed along the carotid artery and internal jugular 

 vein, extending downwards on the sheath of those vessels as far as the 

 thorax. 



The lymphatic vessels of the cranium and face, together with those of 

 the tongue, pharynx, larynx and other parts of the neck, pass into the 

 cervical glands. From these efferent vessels issue, which progressively 

 diminish in number during their descent, and unite into two trunks, of 

 which the left one ends in the thoracic duct, and the other in the right 

 lymphatic duct : sometimes, however, the main cervical lymphatic vessel 

 terminates separately at the junction of the subclavian and internal jugular 

 veins, or in one of those veins immediately before their union. 



The lymphatics of the cranium consist of a temporal and an occipital set. 

 Those of the temporal set descend in front of the ear, some of the vessels 

 passing through one or two glands usually found near the zygoma, whilst 

 others enter those situated on the parotid gland ; all of them terminate in the 

 lymphatic glands of the neck. The cranial lymphatics of the occipital set, 

 accompanying the occipital artery, descend to the glands situated behind 

 the ear, on and near the mastoid process of the temporal bone, and 

 hence join the superficial lymphatics of the neck. 



Within the cranial cavity, lymphatic vessels have been demonstrated in 

 the pia mater and in the arachnoid membrane. None have been traced 

 in the dura mater, nor have they been shown in the substance of the brain. 

 The trunks of those derived from the pia mater pass out of the skull with 

 the veins. 



The superficial lymphatics of the face, more numerous than those of the 



