38o 



THE FROG. PHYLUM CHORDATA 



which the sperms are stored until they are used for fertiHsing the 

 eggs of the female. In the female, the ovaries correspond in 

 position to the testes, the membrane by which each of them is 



i.o.d 



r.V 



cc, . .j^y- a.ab.v. 



ige. — The urinary and genital organs of a female frog. 



Fig. 2 



aabv Anterior abdominal vein, cut short and turned back ; bl., urinary bladder ; cL, cloaca ; e.s., egg sac ; 

 'fb fat body ■ fv femoral vein ; i.o.d., internal opening of oviduct ; i.v.c, mferior vena cava ; k., 

 kidney ■ k d., Wolffian or kidnev duct ; od., oviduct ; ov., left ovary ; ov.v., ovarian vein ■ pl.v. pelvic 

 vein • r I right lung ; r.v., renaf veins ; r.p.v., renal portal vein ; sc.v., sciatic vein ; sr.b., adrenal bodj'. 

 The ovary and fat body of the right side have been removed. A diagram of these organs will be found 

 on p. 381. 



slung being known as the mesovarium. They are pleated folds 

 of peritoneum containing ova in various stages of ripeness, each 

 ovum enclosed in a follicle of smaller cells and all held together 

 by connective tissue. In the breeding season they enlarge and 

 shed the ripe ova into the body cavity, where, by cihary action. 



