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THE REPRODUCTION OF THE EEL. 



By THOMAS SOUTHWELL, F.Z.S., 



Norwich; Me7nber of the British Ornithologists Union \ Author of'' The Seals 

 and Whales of the British Seas.' 



Under the above title a translation of a most instructive paper by 

 Dr. Jacoby ('Die Aalfrage.' By Dr. L. Jacoby. Translated by Her- 

 man Jacobson from ' Der Fischfang in der Lagune von Comacchio 

 nebst einer Darstellung der Aalfrage') on the reproduction of 

 the eel, appears in the Seventh Report of the ' United States 

 Commission on Fish and Fisheries.' As these reports, although 

 most liberally distributed by the United States Government, may not 

 be accessible to a large number of the readers of this journal, a 

 summary of Dr. Jacoby's important contribution to that vexed question, 

 the life history of the eel, may be acceptable. 



Perhaps no single point in the whole wide field of natural 

 science has given rise to more discussion or has more exercised the 

 minds of the leading naturalists for many centuries past, than the repro- 

 duction of the eel. Aristotle, whose original observations, made four 

 centuries before Christ, formed the mine from which for many 

 generations all subsequent natural history not purely imaginary was 

 quarried, must have approached very near to the great discovery of 

 the sexual organ of the female fresh-water eel, for by actual 

 experiment he detected the ovaries of the Conger; nevertheless, 

 failing to recognise the very similar organ in the former species, he 

 confidently asserted that it was not produced by ordinary generation, 

 but spontaneously, from mud and moist soil. Doubtless the weight 

 of Aristotle's authority was such that his assertion long remained 

 unquestioned, and when men's minds again reverted to the subject 

 the most absurd conjectures and assertions were plentifully abundant, 

 but practical research was not the method then in vogue. Some of these 

 absurd theories, which even now are not quite extinct, will be briefly 

 referred to farther on ; suffice it to say that till the year 1777 they had 

 to do duty for the truth, and even now so much remains to be 

 discovered that, as has been well said, * to a person not acquainted 

 with the circumstances of the case it must seem astonishing, and it 

 certainly is somewhat humiliating to men of science, that a fish 

 which is commoner in many parts of the world than any other fish, 

 the herring perhaps excepted, which is daily seen in the market and 

 on the table, has been able, in spite of the powerful aid of modern 

 science, to shroud the manner of its propagation, its birth, and its 

 death, in darkness, which even to the present day has not been 

 completely dispelled.' 



May 1885. L 



