6 



LYMPHATICS IN THE STOMACH OF THE EMBRYO PIG. 



arise the lymphatics of the intestine and of the abdominal structures, while from 

 the anterior lobe spring vessels to the stomach, spleen, duodenum, diaphragm, and 

 lungs (text-figure 2). It is this anterior portion of the sac with which we are pri- 

 marily concerned in this study. The entire sac is obliterated during development, 

 being the primordium for the chain of lymph-glands which reach from the cceliac 

 axis to the bifurcation of the aorta. 



The gastric vessels arise by two main trunks from the anterior lobe of the retro- 

 peritoneal sac. The right trunk is much larger than the left and passes behind the 

 stomach to the lesser curvature, where it invades the stomach at three different 



D.V. 



TEXT-FIO. 2. Diagram of the retroperitoneal sac showing 

 ing the relation of the gastric trunks as> they leave its 

 anterior end. The early lymphatics extending to the 

 pillars of the diaphragm are also illustrated. 



A., Adrenal; D. P., pillar of the diaphragm; D. V., 

 diaphragmatic vessels; H. V., hepatic vessels; K., kidney; 

 R. G. T., right gastric trunk; R. P. S., retroperitoneal sac; 

 V. S. M., vessels of splenic mesentery, W. B., Wolffian 

 body. 



points: (1) the opening of the esophagus, (2) the center of the lesser curvature, and 

 (3) the pyloric extremity of the lesser curvature. These three sets of vessels to the 

 stomach are well shown by a comparison of figures 6 and 7. It can be seen (fig. 6) 

 that another vessel of considerable size is given off from the right trunk, or arises 

 as a separate trunk from the anterior part of the retroperitoneal sac, and passes 

 through the mesentery to the duodenum (A. Duo. V.). It then extends along the 

 duodenum to the pylorus, where it anastomoses freely with the pyloric vessels, 

 reaching the stomach from its posterior surface (fig. 4) . 



The left gastric trunk, or splenic trunk, as it may be called from its distri- 

 bution, divides into two branches. One passes directly to the cardiac pouch and 

 is not shown in the figures; the other passes through the splenic ligament to the 

 hilum of the spleen, the interior of which it has never been seen to enter, and then 



