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FRED W. STEWART 



glia. These cells together with a tracheo-esophageal ganglion 

 are indicated in figure 7. Below the bifurcation of the trachea, 

 ganglia are found between the bronchi; the most caudal of these 

 fuse with the large masses of ganglion cells constituting the 



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Fig. 7 Rat embryo, 17 days, Carnoy's 6-3-1. Neuroblasts of vagus trunk, a 

 tracheo-esophageal ganglion, and developing ganglion cells of the esophageal 

 plexus, Projection drawing, X 500. 



deeper portion of the cardiac plexus. Subsequently this gan- 

 glionic mass gives rise to four (two bilaterally symmetrical) off- 

 shoots (fig. 25) related apparently to the bronchi and seemingly 

 reminiscent of the same fundamental plan of arrangement as 

 that found higher up. Branches from the vagus proper and from 



