HERMAPHRODITE GENITALIA OF THE CODFISH. 000 



Smith TVoodward * have forced them to conclude that both the 

 living Elasmobranchs and Teleosteans are specialized members of 

 their types ; they look upon the two as equally ancient, and as 

 connected with some lower types of greater antiquity, now 

 wholly extinct. Putting all together, I accept their conclusions, 

 except so far as they involve the so-called archipterygial type of 

 fin ; and that the facts and considerations dealt with in this paper 

 tend in the same direction will, I trust, be obvious from the 

 context. 



VI. Lepidosteus is well known to be the only living cystoarian 

 Granoid. Balfour and Parker, when dealing with its reproduc- 

 tive organs, observed that its ovary and ovary-duct pass through 

 an Osmeroid stage {cf. ante, p. 550). On having concluded t 

 that the genital products of the male are transported by vasa 

 eflferentia through the mesoiiephros, they suggested that "the 

 Teleostei must .... have sprung from Ganoids in which the 

 vasa efferentia had become aborted." Jungersen has shown 

 reason for doubting this observation (made only upon one 

 specimen of 60 centim. in length) J; but even if it should hold 

 good, I am of opinion that their suggestion by no means follows 

 as a logical conclusion. Eor equally good arguments might be 

 brought forward to show that Lepi dost ens, instead of repre- 

 senting, as they would have us believe, a type transitional in 

 these respects between Elasmobranchs and other Granoids, might 

 typify a culminatiug term in the Ganoid series as now represented ; 

 the "vasa efferentia," as it were, first appearing instead of 

 languishing. The position of Balfour and Parker assumes that the 

 type of structure exemplified in the urino-genital system of the 

 living Elasmobranchs is necessarily more primitive than that of 

 the Ganoids and Teleosteans. All subsequently discovered facts 

 of comparative embryology of the system named are in complete 

 opposition to this ; and it will, I trust, be admitted that the general 

 structural features of Lepidosteus are most nearly in harmony with 



* British Miis. Oat. Fossil Fishes, vol. ii. pp. xi, xxi (1891). 

 t Phil. Trans. 1882, part ii. p. 424. 

 I Loc. cit. p. 188. 



