PLATE 2 



EXPLANATION OF FIGURES 



25 Rat embryo, 17 days, Carnoy's 6-3-1. Continuation of series of tracheo- 

 esophageal ganglia along bronchi, and into cardiac plexus. Photograph, X 145. 



26 Ratembryo (gray), 5.5 mm., Zenker's fluid. Ramus lingualis IX. Photo- 

 graph, X 180. ! , > "' 



27 Rat embryo, 16 days, Carnoy's 6-3-1. Clusters of neuroblasts along fibers 

 of ramus lingualis IX in tongue. Photograph, X 142. 



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