470 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [8] 



published an interesting dissertation on the sex of the lamprey and the 

 eel, * in which he pronounced Hohnbaum's view as erroneous, and ex- 

 pressed the supposition that male eels were either very scarce, or that 

 they differed in shape from the females. Till the seventh decade of 

 our century no male eel has ever been seen, nor has any opinion been 

 advanced regarding the shape of the male eel and its organs of genera- 

 tion, f By a strange accident the University of Bologna was again 

 destined to open the discussion of the eel question and enter upon a 

 scientific tournament with the University of Pa via. In the session of the 

 Academy of Bologna of December 28, 1871, G. B. Ercolani, professor of 

 anatomy, read an essay entitled, "The complete hermaphroditism of the 

 eel."f Two weeks later two professors of the University of Pavia, Bal- 

 samo Crivelli and L. Maggi, also read a paper on the eel entitled " The 

 principal organs of generation of the eel." These three scientists had, 

 therefore, without the slightest preconcerted knowledge, again taken up 

 the famous discussion of the eighteenth century, this time chiefly with 

 regard to the male organs of the eel. Both parties were convinced that 

 they had at last discovered these organs, and it must be confessed that 

 the results of their investigations were strange enough. In Ercolani's 

 treatise it is shown that the above-mentioned fatty band running along- 

 side of the ovarium is the male'organ (testicle) of the eel ; the left baud, 

 distended by air, being the real testicle, whilst the right one had been 

 in some way checked in its growth, and was not capable of performing 

 its function. In Crivelli's and Maggi's essay, § on the other hand, these 

 fatty bands are likewise described as the testicles of the eel, but with 

 this difference, that the right one is declared to be the only productive 

 organ. These two last-mentioned scientists even give drawings of the 

 spermatozoids, which they say they have observed in the fatty band 

 extending along the right side. As these bands are invariably found 



* " DePetrornyzontuinetAnguillarumsexu." Inaugural dissertation, Dorpat. 1848. 



t Rathke, strange to say, in his above-mentioned treatise on the sexual organs of 

 fish (Halle, 1824), also speaks of the male organs, the testicles of tho eel, and always in 

 connection with those of the lampreys (see p. 128 and p. 158) ; yea, he even 

 describes the inner construction and substance of the testicles of the eel, pp. 185, 18G, 

 187, 190, and 193. It is a positive fact, however, that Rathke has never informed the 

 scientific world of the discovery of a male eel, although in tho above-mentioned article 

 jn "Wiegmann's Archiv" (1838, p. 299) wo find the following sentence: "Regarding 

 the male organs of the eel, I hope to give further particulars at no distant period." It 

 would be interesting to ascertain whether in the posthumous papers of the famous 

 author some notice of or memorandum on male eels which, however imperfect, would 

 be valuable, has been found. 



t Ercolani's essay is entitled, " Del perfetto ermafroditismo delle Anguille," and is 

 reprinted in the "Meniorio dell' Academia delle Scienzo del Istituto di Bologna," 1872, 

 part 4, p. 529. 



§ Balsamo Crivelli's and L. Maggi's essay has been published under the title: " In- 

 torno agli organi essenziali dolla riproduzione delle Anguille" in tho Memoire del 

 Istituto Lombardo di Scienze e Lettere a Milano, " vol. xii, 1872, part 4, p. 229. Ii 

 has been translated into German in "Wiegmann's Archiv fur Naturgeschichte" 187?., 

 part I, p. 59 et seq. 



