466 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [4] 



great zeal, and we have treatises on the procreation of the eel by the 

 most famous naturalists of that "period, such as Eondelet, Salviano, 

 Aldrovandi. This (the sixteenth) and the following century, however, 

 did not get beyond the discussion regarding youug ones said to have 

 been found in eels. I have already mentioned some of the naturalists 

 who held this opinion. Franz Eedi and Christian Franz Paullini, both 

 living in the seventeenth century, were the first who, without, however, 

 having made personal observations, expressed the opinion that eels had 

 both semen and eggs, and that their procreation differed in no wise 

 from that of other fish. 



It was reserved for the eighteenth century at last to discover at least 

 the female organs of the eel, and settle this part of the question defi- 

 nitely. It is an interesting fact that Comacchio has been the birth- 

 place of many erroneous opinions, and of the final truth in this matter. 



Dr. Sancassini, a learned physician of Comacchio, who, in the year 

 1707, visited one of the eel-houses, found an eel whose stomach appeared 

 considerably bloated. He opened it and found inside an organ closely 

 resembling an ovarium, which contained what appeared to him mature 

 eggs. He preserved this eel and sent it to his friend, the famous natu- 

 ralist, Professor Vallisneri, of the University of Padua, who carefully 

 examined the organ and rejoiced that he had at length found the ova- 

 rium of the eel. He wrote a learned treatise on the subject* and sent 

 it to the Academy of Bologna. Strong doubts as to the correctness of 

 this discovery were immediately raised, especially outside of Italy. 

 These doubts seem to have been shared by Professor Valsava, the first 

 anatomical authority of Bologna, especially when soon after another 

 Comacchio physician, Dr. Francesco Bonaveri, author of a "History of 

 Comacchio," sent an eel to Bologna, which in every respect resembled 

 the one described by Vallisneri. t The discussion grew quite animated, 

 and the Bologna scientists seemed actually possessed with a passionate 

 desire to discover the ovaria of the eel. Prof. Pietro Molinelli had prom- 

 ised several fishermen of Comacchio whom he knew a large reward if 

 they would get him a pregnant eel ; and in 1752 a fisherman brought 

 him a live eel, whose stomach was very much bloated, and which, when 

 opened by him in the presence of a friend, was found to be full of eggs. 

 The great hopes connected with this discovery were, unfortunately, not 

 realized, for it turned out that the sly fisherman had previously opened 

 the eel and stuffed it with the eggs of some other fish. The eel ques- 

 tion entered upon another and more successful stage when, in the begin- 

 ning of the year 1777, a third eel, resembling the two former ones, was 

 caught near Comacchio. Luigi Bonafede sent it to the Academy of 



* Published with illustrations at Venice in 1710, and also in 1712, under the title 

 "De ovario anguillarum" in the " Ephemeriden der Leopoldinischen Akademie der 

 Naturforscher." 



t Bonaveri says in his "History of Comacchio" that he is fully convinced of the 

 correctness of Vallisneri's idea and discovery. 



