220 SOUTHWELL: REPRODUCTION OF THE EEL. 



Ercolani, and afterwards Crivelli and Maggi jointly, — al^o led astray 

 by the same appearance which deceived Hohnbaum-Hornschuch, all 

 likewise declared the eel to be hermaphrodite. The cause of their 

 error was, that in addition to the frill-like ovaria already described in 

 the female eel, there will be found running alongside of each of the 

 two ovaria, and extending through the abdominal cavity, an irregular 

 band of fat, with many points, developed more on one side than on 

 the other ; this, w^hich is merely ' a fold of the inner skin of the 

 abdomen,' the anatomists before referred to mistook for the male 

 organ of the eel, and as these folds are invariably found in all eels 

 having an ovarium they must necessarily, had this view been the 

 correct one, have been complete hermaphrodites. Even so late as 

 April 1874, Prof MUnter of Greifswald, after having examined 

 3,000 eels, his researches extending over a period of several years, 

 and never having met with a male fish, finds himself compelled to 

 'admit that eels are reproduced by parthenogenesis — i.e., from 

 non-fecundated eggs, as is the case with some insects.' It was not 

 till November 1873 that Dr. Syrski, then of Trieste, commenced his 

 investigations, which in the second eel he dissected were crowned 

 with success, and the long-debated problem of the sexual difference 

 in the eel was solved. But even then the matter was not perfectly 

 conclusive, owing to the absence of spermatozoids ; in September 

 1877, however, Dr. Jacoby obtained an eel with the male organs in a 

 more advanced stage of development, in which their inner con- 

 struction showed ' tube-like ducts filled with cells, exhibiting an 

 unmistakable resemblance to the seminal cells of the testicles of other 

 fish'; and so the matter rests at the present time, for in no case has an 

 individual with fully developed organs of either sex been found. Syrski 

 describes the spermatic organs of the eel as situated like the ribbon- 

 shaped ovaries and consisting of two longitudinal rows, each of about 

 fifty lobules of the width, at most, of three millimetres ; they will be 

 found ' by carefully turning over and laying back the fatty folds ' 

 which have been before spoken of as found in the female eel in 

 addition to the ribbon-shaped organ, but the lobe-shaped band 

 fastened to the backbone is often so narrow, and its substance so 

 glass-like and transparent, that when attached to its base it can only 

 be recognised with the naked eye when it is held in an oblique 

 direction towards the sun. 



Dr. Jacoby, during a visit paid to the great Eel Fishery at 

 Comacchio, at the mouth of the Po, undertaken fpr the express 

 purpose of further studying the ' eel question,' made some important 

 additions to the knowledge of the life history of the eel, and, amongst 

 other things, learned to distinguish the male from the female eels by 



Naturalist, 



