THE FEMALE EEL. 637 



DISCOVERY OF THK FEMALE EEL. A scientific investigation into the generation of Eels 

 could only begin when, at the end of the Middle Ages, the prohibition which the veneration for 

 Aristotle had thrown over the investigations of learned men wa.s thrown aside. With the revival 

 of the, natural sciences in the sixteenth century we find that investigators turned themselves with 

 great zeal to this special question. There are treatises upon the generation of the Eel written by 

 the most renowned investigators of that period, such as Rondelet, Salviani, and Aldrovandi. 

 Nevertheless, this, like the following century, was burdened with the memory of the numerous 

 past opinions upon the eel question, and with the supposed finding of young inside the body of 

 the Eel. 



The principal . supporters of the theory that the Eel was viviparous were Albertus Magnus, 

 Leeuwenhoek, Eisner, Eedi, and Fahlberg. The naturalists Franz Eedi and Christian Franz 

 Paulliiii, who lived in the seventeenth century, must be mentioned as the first who were of the 

 opinion, founded, however, upon no special observations, that the generation of the Eel was in no 

 respect different from that of other fishes. 



In the eighteenth century it was for the first time maintained that the female organs of the Eel 

 could certainly be recognized. It is interesting that the lake of Comacchio was the starting 

 point for this conclusion as well as for many of the errors which had preceded it. The learned 

 surgeon Sancassini, of Comacchio, visiting an eel fishery at that place in 1707, found an Eel 

 with its belly conspicuously enlarged; he opened it and found an organ resembling an ovary, and, 

 as it appeared to him, ripe eggs. Thereupon he sent his find, properly preserved, to his friend, the 

 celebrated naturalist Vallisueri, professor in the University of Padua, who examined it carefully, 

 and finally, to his own great delight, became satisfied that he had found the ovaries of the Eel. 

 He prepared an elaborate communication upon the subject, which he sent to the Academy at 

 Bologna. 1 



At the very beginning there were grave questions raised as to the correctness of this dis- 

 covery. The principal anatomical authority at Bologna, Professor Valsalva, appears to have 

 shared these doubts, especially since shortly after that a second specimen of Eel, which presented 

 the same appearance as that which was described by Vallisueri, was sent from Comacchio to 

 Bologna. The discussion continued, and it soon came to be regarded by the scientific men of 

 Bologna as a matter of extreme importance to find the true ovaries of the Eel. Pietro Molinelli 

 offered to the fishermen of Comacchio a valuable reward if they would bring him a gravid Eel. 

 In 1752 he received from a fisherman a living Eel with its belly much distended, which, when 

 opened in the presence of a friend, he found to be filled with eggs. Unfortunately the joyful 

 hopes which had been excited by this fortunate discovery were bitterly disappointed when it was 

 shown that the Eel had been cunningly opened by the fisherman and filled with the eggs of 

 another fish. The eel question came up again with somewhat more satisfactory results when, in 

 the year 1777, another Eel was taken at Comacchio which showed the same appearance as the 

 two which had preceded it. This Eel was received by Prof. Gaetano Monti, who, being indisposed 

 and unable to carry on the investigation alone, invited a number of his favorite pupils, among 

 whom was the celebrated Camillo Galvani, the discoverer of galvanism, to a council at his 

 house. This Eel was examined by them all, and pronounced to be precisely similar to the one 

 which had been described by Vallisnc-ri seventy years before. It was unanimously decided that 

 this precious specimen should be sent for exhaustive examination to the naturalist Mondiui, who 



1 1 fail to find any record of the publication of this paper, except that given by Jacoby, who states that It was 

 printed at Venice in 1710, with a plate, aud subsequently, in 1712, under the title " De ovario Anguillarum," in (.he 

 Proceedings of the Leopold Academy. 



