HEBMAPHRODITB a^NITALIA OF THE CODriSH. 549 



they are (as lias been already suggested for that of the females by 

 McLeod *, Brock t, and Max Weber J) independent structures 

 sui generis. At the same time I consider it not improbable, 

 from the facts afore cited, that the posterior moiety of the 

 Miillerian duct of at least the Amphibia and Amniota may be 

 the vestige of that which has survived in the Teleostei, and that 

 its anterior moiety is a more recent structure which has re- 

 placed the latter in time. 



Brock inclines to the belief that the hermaphroditic condition 

 of the genital glands has been independently evolved within the 

 vertebrate phylum, I venture to think that had the discoveries 

 of Cunningham and Nansen {ante, p. 543) preceded Brock's, 

 he would have arrived at a different conclusion. These and 

 the constantly hermaphroditic habit of the Tunicata appear to me 

 irreconcilable with his supposition, to say nothing of the facts 

 which I have emphasized in dealing with the Teleostei {ante, 

 p. 545) and of Langerhans' discovery of spermatozoa in the ovary 

 of Ampliioxus. While I entirely disagree with Brock's second 

 proposition, I fully acquiesce in his first, and with Beard § regard 

 both Teleostei and Granoids as at all stages wholly destitute of 

 Miillerian ducts. The genital duct of these fishes is, like the 

 gland which it serves, hermaphroditic in tendency ; and, in 

 view of the facts and considerations with which I have dealt, 

 I consider that their rejDroductive system may, most satisfac- 

 torily and with some foundation, be regarded as the most 

 generally primitive among living Grnathostomata. 



IV. Huxley, in 1883, drew attention || to the lack of apprecia- 

 tion which has attended Eathke's observations on the genital 

 ducts of fishes ; and he proceeded to describe the parts now in 

 question in the female 8melt {Osmerus eperlamts), showing them 

 to be readily harmonizable with those of the other Salmonoidei 

 and Granoids, Lepidosteus excepted. The Smelt's ovary is, as 



* Arch. d. Biol. vol. ii. p. 497 (1881). 



t Zeitschr. wiss. Zool. Bd. xliv. p. 375 (188fi). 



I Morph. Jahrb. Bd. xii. p. 396 (1887). 

 § Auat. Anz. 1890, p. 158. 



II Proc. Zool. See. Lond. 1883, p. 132. 



39* 



