DEVELOPMENT OF THE OVIDUCT IN THE FROG. 281 
running ventralwards from primitive funnel of the oviduct. MW. d. Wolffian 
duct (ureter). Wds. Thickening of Wolffian duct. 
Fic. 1.—Transverse section of Frog 38 mm, long, including a tail of 
17 mm. Section is through level of hind brain. pz. f. Pronephric funnel. 
m. f. Oviducal funnel. 
Fig. 2.—Transverse section of the same series as Fig. 1 a little further 
back. md. Solid rudiment of oviduct. 
Fic. 3.—Transverse section of a Frog 13 mm. long, including a tail of 
1 mm. at same level as Fig. 1. pz. ¢. degenerate pronephric tubules. v. g. 
Groove which runs ventralwards from primitive dorsal funnel of the oviduct. 
Fic. 4 is Fig. 3 under a lower power, showing the whole section. Jz. 
Integument. Jy. subintegumentary lymph space. 
Figs. 5 a, 6, c-—Three sections from aseries cut from a Frog 13°5 mm. long 
with no tail. Sections about same level as all preceding. Ly. is lymphatic 
space above lung. 
Fies. 6 a and 4.—Two sections from a series cut from a Frog 14°5 mm. 
long with no tail. Same level as Fig. 5. Ziv. Liver. 
Fic. 7.—Transverse section through the same Frog as Fig. 1 behind pro- 
nephros, but in front of kidney. Wd. Wolffian duct. 
Fic. 8.—Transverse section through the same Frog as Fig. 3 in same 
place as Fig. 7. 
Fic. 9.—Transverse section through the kidney of same Frog as Fig. 5. 
kt. One of the kidney tubules. Zy. Lymphatic space above kidney. 
Fic. 10.—Transverse section through the kidney of a Frog 16 mm. long 
with no tail. 
Fic. 11.—Transverse section through the kidney of a Frog 16°5 mm. long 
with no tail. 
Fic. 12 is a section of the same Frog as Fig. 10 under a lower power. 
M. Mesentery. Ov. Ovary. Jy. Lymphatic dorsal to the kidney. 
Fie. 13.—Transverse section behind kidney of same Frog as Fig. 11. 
Wds. Thickening of the wall of the Wolffian duct apparently a rudiment of 
vesicula seminalis. 
Fie. 14.—Transverse section through the cloaca of same Frog as Fig. 11. 
Md. Oviducts, solid rudiments, one touching the cloacal wall. 
VOL, XXXIII, PART II.—-NEW SER. ah 
