240 



ZOOLOGY 



o-vcL' 



ozfoL'- 



ovd. 



seminal fluid escapes into the coelome and is discharged by genital 

 pores. 



In most Ganoids the ovidiccts (Fig. 897, B, ovd) have funnel-like 

 anterior ends {ovd.") opening into the coelome, while posteriorly 

 {ovd.') they discharge into the dilated ureters {hi). A similar 



arrangement occurs 

 in the Smelt, one 

 of the Physostomi 

 (Salmonidse), in 

 which the eggs are 

 discharged from the 

 outer or lateral face 

 of the ovary into 

 the open end of the 

 oviduct. But in 

 most Teleostei and 

 in Lepidosteus (Fig. 

 897, A) the ovary 

 {ovy.) is a hollow 

 sac continued pos- 

 teriorly into the 

 oviduct {ovd.) : the 

 eggs are set free 

 into its cavity from 

 the folds into which 

 its inner surface is 

 produced, and so 

 pass directly into 

 the oviduct without 

 previously entering 

 the coelome. An 

 ovary of this kind 

 reminds us of the 

 state of things in 

 Arthropods, in 

 which also the ovary 

 is a hollow organ 

 discharging its pro- 

 ducts into its inter- 

 nal cavity, whence 

 they pass directly into the continuous oviduct. It was pointed out 

 that the lumen of the ovary in this case was to be looked upon as a 

 shut-off portion of the coelome: this is certainly the case in Lepi- 

 dosteus and the Teleostei. In the embryo a longitudinal fold grows 

 fi'om the ventral edge of the then solid ovary, and turns upwards 

 along the lateral face of the organ : it is met by a descending fold 

 of peritoneum from the dorsal wall of the abdomen, and by the 



-u.^ap 



Fig. 897.— Female organs uf liepidosteus (A) and Amia (B). 



a, degenerate anterior portion of kidney ; bl. bladder ; kd. 

 kidney ; ovd. oviduct ; ovd.' aperture of oviduct into bladder; 

 ovd." peritoneal aperture ; ovy. ovary ; p. peritoneum ; 

 u.g. ap. urinogenital aperture ; ttr. ureter. (A, after Balfour 

 and Parker ; B, after Huxley.) 



