88 Florence E. Sabin. 



Along the trachea is a group of nodes, of which the mass at the 

 bifurcation is especially large. Nodes are also seen along the bronchi 

 within the hilum of the lung, and large lymph vessels extend into 

 the pleura while smaller ones are to be seen in the septa of the lung 

 itself. No nodes are to be made out within the lung. 



The thoracic duct is easy to follow as a plexus of vessels along 

 the aorta. Along the vertebral column there are three chains of 

 lymph nodes — one on either side of the bodies of the vertebrae not 

 far from the mid-line and closely associated with the thoracic duct. 

 The other two sets are farther to the side, against the body of the 

 vertebrae near the base of the transverse processes. These drain the 

 body walls. So abundant are these vertebral lymph nodes that 

 scarcely a section lacks them, the sections being 100 microns thick. 



In passing into the abdominal cavity the cisterna chyli is readily 

 located. Along its lateral borders is a complete chain of nodes, 

 and at the lower end is a large clump of similar nodes. 



The retroperitoneal sac has been transformed into a group of 

 nodes except at the upper end, just below the superior mesenteric 

 artery where the sac still persists. Fig. 18 is taken just below the 

 more open part of the sac and shows the bridging and some extension 

 of the sac to the right. The retroperitoneal sac then becomes the 

 group of nodes ventral to the aorta. It will be remembered that at 

 the beginning, the sac extended along the veins of the adrenal bodies. 

 At this stage there is an extensive mass of lymphatic tissue contin- 

 uous with the mesenteric sac, extending along the hilum of the 

 suprarenal bodies. The same mass of lymphatic tissue lies at the 

 base of the mesentery at the portal of the liver. In no section, 

 however, are there any nodes within the hilum of the liver. 



The most extraordinary development has taken place in the 

 mesentery. A group of nodes follows the pancreas and there is a 

 small node at the hilum of the spleen. A similar node lies against 

 the stomach. In the center of the mes,entery is an exceedingly large 

 node, measuring 2 mm. on a side, see Fig. 18. This large central 

 lymphatic mass in the mesentery is connected with the mesenteric 

 sac by a chain of nodes running along the superior mesenteric 

 artery. From this central mass vessels run out in the mesentery 

 toward the intestine. 



