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Part III. — Fifteenth Annual Report 



XIV.— NOTE ON THE REPRODUCTIVE ORGANS OF A 

 HERMAPHRODITE LING. By H. M. Kyle, M.A., B.Sc. 



Another form has to be added to the list of fishes in which hermaphro- 

 ditism is known to occur, viz., the ling (Molva vulgaris). As this 

 form is grouped under the same family, and closely allied to the common 

 cod, which presents numerous instances of hermaphroditism, it is hardly 

 to be wondered at that the same phenomenon should occur in it. This is 

 but another example which shows the truth of the dictum — that the most 

 abundant and most widespread orders are the most liable to show varia- 

 tions. Professor Howes points out, in his paper on the ' Hermaphrodite 

 Genitalia,' etc. in the Linnxan Soc. Jour., vol. xxiii., that this phenomenon 

 is known in six orders, four of which contain the most widespread 

 forms : one of them, indeed, including a larger number of fish than is 

 included under all the other orders put together. 



A specimen of the hermaphrodite ling (the first that has been found 

 and recorded up to this time, I believe) was taken off Lerwick, in Shet- 

 land, on the 14th May of this year. The reproductive organs were 

 forwarded by the courtesy of Mr Duthie, assistant fishery officer, and 

 Professor M'Intosh has kindly handed them to me to describe. Certain 

 particulars with regard to the appearance of the fish were sent to Professor 

 M'Intosh, from which one could gather that it looked like a young 

 female ling, about one-third the full size, with a head rather smaller than 

 is usual. From this description it might be inferred that the female 

 reproductive organs were more developed than the male, but in reality, 

 as will be shown, both were equally developed. 



The reproductive organs are most remarkable, a good-sized ovary on 

 each side being connected with a well-developed testis, which is at least 

 five times as large as the ovary. 



On the one side, the right, the full length of the organ is 15*4 cm., 

 the ovary situated at the posterior end being 4"8 cm. long by 3 "2 in 

 diameter. The ovary is barrel-shaped, of a yellow colour, and full 

 of ova, most of them almost ripe, the largest being "71 mm. The 

 external coat is strong, thick, and fibrous, giving rise internally to the 

 leaf-like folds on which the ova are borne. These folds, as is usual in 

 the group, project into a central cavity which posteriorly opens into a 

 short, wide duct. This duct, which is common to the ovaries on both 

 sides, opens to the exterior. Close to the posterior end is a small piece 

 of testis, springing from the coat of the ovary. This peculiar position, at 

 a distance from the remaining parts of the testis, may be compared with 

 a similar phenomenon found in the cod, and described by Mr Masterman 

 in the Thirteenth Report of the Fishery Board (1894). 



Anteriorly, the fibrous covering of the ovary is continued over the 

 connection to the multi-lobed testis. Over this it extends also, but 

 changes its colour from yellow to white. On the dorsal surface of the 

 ovary, and running along the duct that leads from the testis into the 

 ovary, is the genital artery. The lobes of the testis (about sixteen in 

 number) are much folded and convoluted, and are arranged round the 

 duct and blood-vessel in a spiral manner. 



The organ on the left side is even more complicated than that of the 

 right. 



The ovary is situated between two portions of the testis, and the ovary 



