426 



MANUAL OF ZOOLOGY 



SECT. 



coating of this substance as they pass down the oviducts and 

 are finally stored up in the thin-walled posterior portions of 



FIG. 241. Rana esculenta. Urinogenital organs of the female. N. kidneys ; 

 Od. oviduct ; Ot, its ccelomic aperture ; Otr. left ovary (the right is removed) ; 

 P, cloacal aperture of oviduct ; 6". S' . cloacal apertures of ureters ; Ut. uterine 

 dilatation of oviduct. (From Wiedersheim's Comparative Anatomy.) 



those tubes, which, in the breeding season become immensely 

 dilated and serve as uteri. 



The eggs are laid in water in large masses ; each has one 



