224 



ZOOLOGY 



SECT. 



3 



Ad 



ur 



so pass directly into the oviduct without previously entering the 

 ccelome. An ovary of this kind reminds us of the state of things 

 in Arthropods, in which also the ovary is a hollow organ discharg- 

 ing its products into its internal 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 



v 



in Lepidosteus and 

 Teleostei. In the 

 embryo a longitu- 

 dinal fold grows 

 from 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 union of the 

 two . folds a cavity 

 is enclosed, which is 

 the lumen of the 

 ovary. The oviduct 

 is developed as a 

 backward continua- 

 tion of these folds 

 of peritoneum, and 

 appears to be quite 

 unconnected with 

 the embryonic ne- 

 phridial system, and 

 therefore not to be 

 homologous with 



the oviducts of Elasmobranchs and Holocephali, which, as we 

 have seen, are Miillerian ducts. In the Salmonida? and the 

 Eels oviducts are absent, and the ova are discharged by genital 

 pores, which are probably to be looked upon as degenerate 

 oviducts. True abdominal pores are present in Ganoids and in 

 some Physostomi. Most Teleostomi are dioecious, but Serranus, 

 one of the Perch family, is hermaphrodite and self-impregnating, 



ovcL'~ 



FIG. 847. Female organs of Lepidosteus (A) and Amia (B). 

 a, degenerate anterior portion of kidney ; W. bladder ; M. 

 kidney ; ovd. oviduct ; onl. 1 aperture of oviduct into bladder ; 

 ovd." peritoneal aperture ; ory. ovary ; />. peritoneum ; 

 u.g. ap. urine-genital aperture ; ur. ureter. (A, after Balfour 

 and Parker ; B, after Huxley.) 



