192 W. 1\ E. WELDON. 



EXPLANATION OP PLATES XVIII & XIX, 



Illustrating Mr. W. F. R. Weldon's Paper "Ou the Supra- 

 renal Bodies of Vertebrata." 



Complete List o/Re/erenee Letters. 



Al. Alimentary canal. Ao. Aorta. Bv. Blood-vessel, c/l. Glomerulus. 

 g. ep. Glomerulus epithelium, pe. ep. Peritoneal epithelium. Mes. Mesentery. 

 V. 0. Vena cava. s. t. Segmental tubule, s. str. Testicular tubule, s. r. b. 

 Suprarenal blastema. W. r. Wolffian ridge. 



The figures were in all cases drawn by the aid of a Zeiss's camera luoida. 



ElG. l.^Transverse section through a glomerulus of an embryo ofLacerta 

 muralis with twenty-one protovertebree. 



Fig. 2. — Similar section through an embryo with twenty-three protover- 

 tebrae. 



Fig. 3. — Similar section through an embryo 8 mm. long. 

 Fig. 4. — Similar section from an embryo 10 mm. long. 

 Fig. 5. — Similar section from an embryo of 11 mm. 

 Fig. 6. — Similar section from an embryo of 13 mm. 

 Fig. 7. — Similar section from an embryo of 18 mm. 

 Fig. 8.— Transforming blastema of teleostean kidney, copied from Emery. 

 Figs. 9 and 10. — Two consecutive sections through an embryo of Pris- 

 tiurus melanostomus of 8 mm. 



Figs. 11—13. — Consecutive sections from an embryo of Pristiurus of 83 mm. 

 Figs. 14 and 15. — From an embryo of Pristiurus of 10 mm. 



Fig. 16.— From an embryo of Pristiurus slightly older than that figured in 

 figs. 14 and 15. 



Fig. 17. — From a five-day chick. 



Fig. 18. — From a seven-day chick. 



Fig. 19. — From a nine-day chick. 



