PLATE 4 



EXPLANATION OF FIGURES 



Injections of the second period. Figure 5 is a drawing combined from two 

 specimens. The heart plexus and all remaining vessels of the picture are drawn 

 from no. 24, while the vessels extending anteriorly are from no. 26. Longitudinal 

 tracts are conspicuous in the lymph heart plexus (E. palustris). 



Figures 6 and 7 were drawn by Miss Brinton, from specimens of the same 

 period, the injection in figure 6 (E. catesbiana) having failed to invade the 

 plexuses, runs only through the main vessels. This is a demonstration of the early 

 segmental character assumed by the lymphatics along the veins, similar to the 

 condition found in urodeles. The main dorsal lymphatic has reached far back 

 into the tail. The jugular lymphatic is represented in its early condition, as a 

 plexiform channel. In figure 7 the dorsal lymph plexus and its connection far 

 anteriorly with the dorsal heart vessels are demonstrated. 



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