xv REPRODUCTIVE ORGANS 405 



female, seems to be a duct sui generis and to have no con- 

 nexion whatever with the kidney system (Fig. 230, E). In the 

 Salmonidae, Anguilliclae, Galaxiidae, Hyodontidae, Notopteridae, 

 and Osteoglossidae, and also in Misgurnus, the oviducts lose 

 their continuity with ovaries and degenerate to an extent which 

 differs greatly in different families. Thus in some Salmonidae, 

 as in the Smelt (Osmerus eperlanus), 1 the oviducts end anteriorly 

 in wide funnel -like coelomic apertures after the fashion of 

 Mullerian ducts, and do not embrace the ovaries : hence the 

 ovaries are naked and not cystoarian, and their ducts are 

 not peritoneal tubes but "peritoneal funnels" (Fig. 230, F). 

 In other Salmonidae and in the Anguillidae the oviducts appear 

 to have so far degenerated that they are represented either by a 

 pair of very short funnels or by a pair of genital pores, which, as 

 in the Salmon, have a common external aperture behind the anus 

 and in front of the single orifice of the united archinephric ducts 

 (Fig. 233, A). In all such instances the eggs are set free from 

 the ovaries into the coelom, from whence they escape through 

 the peritoneal funnels or genital pores. In the Eels the male 

 gonoducts also degenerate, and, losing all connexion with the 

 testes, they become reduced to genital pores as in the female. 



The Holocephali and probably the Dipnoi conform to the 

 Elasmobranch type in the nature of their male and female gono- 

 ducts. In the Crossopterygii 2 each testis has its own proper duct, 

 which has no connexion with the kidney system and apparently 

 belongs to the Teleostean type, while the oviduct, which is almost 

 certainly not a Miillerian duct, is probably a peritoneal funnel. 

 On the other hand, the Chondrostei and the Holostei are in the 

 interesting transitional condition of possessing male ducts of 

 the Elasmobranch type and female ducts of the Teleostean type, 

 the latter being either ducts directly continuous with the ovaries, 

 as in Lepidosteus, or of the nature of peritoneal funnels, as in 

 Acipenser, Polyodon, and Amia (Fig. 230, E and F). 



How far the distinction between the two types of gonoduct 

 holds good in the case of the male is not quite clear, and it has 

 recently been argued that the Dipnoi offer a connecting link 

 between the two. 3 



1 Huxley, P.Z.S. 1883, p. 132. 



2 Budgett, Trans. Zool. Soc. xv. 1901, p. 323 ; xvi. 1902, p. 315. 



3 Graham Kerr, P.Z.S. 1901, p. 484; Proc. Phil. Soc. Cambridge, xi. Tt. v. 

 1902, p. 329. 



