Chap, vni.) THE TONGUE. 125 



The tongue contains much lymphoid tissue, a 

 considerable part of which is massed under the 

 mucous membrane at the posterior part of the organ. 

 The lymphatics also are large and numerous, and for 

 the most part follow the ranine vessels. With regard 

 to glandular infection in lingual cancer, it is well to 

 note that these lymphatics enter one or two small 

 glands lying on the hyo-glossus muscle before they 

 reach the deep glands in the neck, where they finally 

 end. 



In the strange congenital affection known as macro- 

 glossia the tongue becomes much enlarged, and in some 

 cases may attain prodigious dimensions. Thus, in one 

 case it measured six and a half inches in length and 

 ten inches in circumference. It has protruded so far 

 from the mouth as to reach even to the episternal 

 notch. It has been so large as to deform the teeth 

 and alveolus, and in one case dislocated the jaw. 

 The enlargement is primarily due to the greatly 

 dilated condition of the lymphatic channels of the 

 organ (hence the name, lymphangioma cavernosum, 

 proposed by Virchow), and to an increased develop- 

 ment of lymph tissue throughout the part. The 

 portion most conspicuously affected is the base of the 

 tongue, where the lymphatics are usually the most 

 numerous. 



A dermoid cyst may be met with on the under 

 surface of the tongue. It is usually placed in the 

 median line between the genio-hyo-glossi muscles. 

 Such cysts are probably due to some infolding of the 

 integumental layer during development. 



Accessory glands about the tongue. 

 Streckeisen states that accessory glands, belonging to 

 the thyroid body, are frequently found in the vicinity 

 of the hyoid bone. Some may be superficial to the 

 mylo-hyoid muscle, others may be just above the hyoid 

 bone, and others in the hollow of that bone. Cysts 



