PLATE 9 



EXPLANATION OF FIGURES 



23, 24 and 25 Transverse sections to show three additional levels of the lym- 

 phatic rudiment illustrated in the sketches on plate 8. Series 52, slide 3, row 

 6, sections 4, 11, 13. X 1100. 



26 Transverse section of a 6 mm. toad embryo through approximately the 

 same region (of. figs. 17-25) to show an earlier condition, evidently, of the superior 

 lateral lymph duct. Series 53, slide 4, row 5, section 17. X HOC. 



REFERENCES 



I., anlage of superior lateral lymph duct 

 i.v., intersegmental vein 



ep., epidermis 



m.s., muscle segment 



27 Transverse section of a 6 mm. toad embryo at the level of the left anterior 

 lymph heart. Series 53, slide 3, row 3, section 13. X 1100. 



REFERENCES 



l.h., posterior portion of the anterior 



lymph heart 

 I., anterior extent of the developing 



inferior lateral lymph duct 

 ■i.v., intersegmental vein 



p.m., p.L, medial and lateral divisions 



of the postcardinal 

 6.C., blood corpuscles 

 C.C., coelomic cavity 

 ep., epidermis 

 m.s., muscle segment 



200 



