1128 



THYROID GLAND. 



At the bifurcation of the trachea into the bronchi, there are a number 

 of hard, black glands, which are lymphatic in their character, and 

 called bronchial from their position. The bronchi are essentially of 

 the same structure and arrangement as the trachea ; the right bron- 

 chus is shorter and of a larger diameter than the left ; they soon 



Fig. 112. 



ramify into numerous subdivisions, which finally terminate in the 

 lobules of the lungs. In the smaller ramifications of the bronchi 

 there is some modification of structure ; the tube is no longer flattened 

 behind, because the cartilages form complete circles ; each cartila- 

 ginous ring is not composed of a single piece, but of several seg- 

 ments of a circle ; there is also a semilunar cartilage at each of the 

 lesser bifurcations. 



THYROID GLAND. 



It is situated in front of the first rings of the trachea, and upon the 

 sides of the larynx; it consists of two lateral lobes, placed on either 

 side, united by a narrow isthmus in front ; it is extremely vascular, 

 of a brownish colour, and of tolerably firm consistence. It is gra- 



