of the Fishery Board for Scotland. 



297 



XL— ON HERMAPHRODITISM IN THE COD. By Arthur T. 

 Masterman, B.A. (Cant.), Assistant Professor of Natural History 

 in the University of St Andrews. 



Two interesting examples of this peculiar abnormality in Gadus 

 morrhua have come under my notice and are described here. 



The first specimen (the dorsal view of which, reduced by two-thirds, is 

 shown in fig. 14, Plate IV., Twelfth Report) was taken from a cod 

 which was caught at Dunbar in the month of February (?), and was 

 forwarded to the University Museum. Through the kindness of Pro 

 fessor M'Intosh I was enabled to make a detailed examination of it, the 

 results of which will be indicated below. 



The second specimen (fig. 11, Plate III., Twelfth Report) was found 

 in a cod which was caught in May, and its occurrence was notified by 

 Mr Gibson, fish merchant, Leith. I have to thank this gentleman for 

 allowing me a superficial examination of this specimen after it was 

 preserved in spirit. 



In No. 1 the two ovaries were apparently normal, their contents being 

 at the same stage of development as those of most cod caught at that 

 time of year. All appearances point to the conclusion that they were 

 perfectly functional. The right ovary was 3 \ inches long (8*125 cms.) 

 and the left was slightly shorter, being 2| inches (6 9 cms.) ; there was 

 little difference in the breadth, and none discernible in the structure, 

 except in that at the anterior extremity of the right ovary was attached a 

 small testis (te) y the comparative size of which can be seen in the figure. 



This organ also, both in its external and internal structure, appeared to 

 be perfectly normal, except perhaps for the fact that the testis was less 

 deeply folded than is usually the case. 



The fibrous covering of the ovary was continued directly on to the 

 testis, forming a short tubular connection between the two. 



The relations and appearance of the connecting duct are seen in fig. 15, 

 Plate IV., Twelfth Report, Here we note that the duct, leading by branches 

 from the inner cavity of the testis, is lined for some part of its length by 

 small longitudinal ridges. It leads by a small aperture into the cavity of 

 the ovary, and just ventral to this aperture there runs a horizontal ridge 

 or fold of the ovary wall, which is to a large extent moveable, and can be 

 conceived as capable of functioning as a valve for preventing the passage of 

 the ova into the testis or testis duct, were such an arrangement needed. 



The only other detailed account of the inner structure of the testis duct 

 of abnormally hermaphrodite piscine organs is that of Professor Howes.* 

 He gives a diagram of the structures, and describes them as follows : — 

 'On laying open the duct I found it to be a spacious tube, honeycombed 

 ' in the manner of that of the normal male over its upper and inner areas. 

 ' Its lower moiety was longitudinally subdivided by a kind of septum 

 ' which shut off a small orifice, placing it postero-externally in communi- 

 1 cation with the interior of the ovary. There arose from the postero- 

 ' internal wall of the ovarian capsule a stout membranous fold which 

 ' projected inwards and passed, for a distance of 1 cm., towards the orifice 

 ' of communication with the testis-duct ; on nearing that it expanded to 

 1 form a well-marked valve-like structure.' 



It will be seen from this that my specimen differed in the structure of 

 its testis-duct only in the absence of the longitudinal 1 septum,' which may 

 be represented in this case by the longitudinal ridges already referred to. 



It is interesting to note that the single testis in the specimen described 

 by Professor Howes was situated at the posterior extremity of the right 



* G. B. Howes, "Hermaphrodite Genitalia of the Codfish, &c," Linncan Society's 

 Journal, xxiii. 



