THE THYROID GLAND. 589 



Fig. 416. 



The vesicles of the thyroid gland, filled with colloid matter. Magnified 50 diameters. 



(Kolliker.) 



The following is Dr. Beale's analysis of the thyroid body : 



Water ....'... 70.60 

 Fibrinous and albuminous matter, vessels, 



and fat . 26.384 



Extractive matter 1.70 



Alkaline salts .50 



Earthy salts .816 



The bloodvessels of the thyroid are disproportionally numerous. 

 The terminal arteries are distributed in the stroma between the 

 vesicles, and end in a capillary plexus around each of them, resem- 

 bling that of the air-cells of the lungs, except that it is less close. 

 The veins only partially accompany the arteries, much exceeding 

 them in number. Of the considerable number of lymphatics, the 

 relations in the interior are unknown. The few nerves contain only 

 vascular nerve-fibres from the cervical portions of the sympathetic. 

 (Kolliker.) 



The function of the thyroid is unknown. It is probably a diver- 

 ticulum to the cerebral circulation; and is developed from an offset 

 from the anterior wall of the pharynx. 



Pathological enlargements of the thyroid (bronchocele) are very 

 common. These may be due ls, to numerous dilatations of the 

 smaller vessels, the bursting of which may also produce apoplectic 

 cysts, to which fresh extravasations, or exudations and cretification 

 of the vessels may be added ; or, 2dly t to an actual hypertrophy of 

 the glandular elements, or a production of new gland-vesicles. 



