472 REPORT OF COMMISSIONER OP FISH AND FISHERIES. [10] 



principally to small eels. Hithertp the largest eels had been picked ont 

 for purposes of scientific examination, because people reasoned in this 

 wise, that the larger and, therefore, the older the eel the farther devel- 

 oped their organs of generation must be. As early as the 2d of January, 

 1874, Syrski found in the second eel which he examined, and which 

 measured 40 centimeters in length — the specimen in question has been 

 preserved in the Museo Civico in Trieste — an entirely new organ which 

 no scientist had hitherto discovered in an eel, although thousands and 

 tens of thousands of eels had been examined.* Syrski published his 

 discovery in the number for April, 1874, of the " Abhandlungen der 

 Kaiserlichen Akademie der Wissenschaften zu Wien." The most im- 

 portant feature of the new discovery was, that in all those eels which 

 contain Syrski's organ the frill-like ovarium, the female organ of gen- 

 eration, was entirely wanting. This proves in the first place that the 

 eel is not a hermaphrodite. But now the question arises : Does the 

 newly discovered organ, both as to its outward form and inner construc- 

 tion, differ so much from the ovarium that it is out of the question to 

 consider it as an irregularly developed or sickly ovarium? After all the 

 preceding investigations, it must be considered highly probable that the 

 newly-discovered organ is really the long-sought-for male organ of gen- 

 eration of the eel, but as yet it cannot be asserted with absolute cer- 

 tainty, because the most important proof, the presence of spermatozoids, 

 has so far not been furnished. 



The first important difference between the newly-discovered organ and 

 the ovarium, which in itself is a strong point in favor of declaring the 

 former to be the testicles, is the presence of a seminal duct, which, wheu 

 filled with air or quicksilver, can be distinctly recognized with the naked 

 eye, and which by its base is attached to and runs along the whole 

 length of the organ. The ovarium never has any duct of this kind, no 

 indication even of ovarian ducts, so that the eggs when ripe fall into the 

 abdominal cavity, and from there through two very small genital aper- 

 tures, which were discovered by Rathke, into the outer world. In the 

 second place, the outward shape of the newly-discovered organ, at any 

 rate in eels which are not too diminutive, differs very much from the 

 well-known ovarium. The organ which occupies the same place in the 

 abdominal cavity as the ovarium does not show the slightest trace of 

 the characteristic frill-like folds, but appears more like a very narrow, 

 light band,t whose free edge, protruding into the abdominal cavity, 



*If we remember that in our times Professor Miintlier alone has opened and exam- 

 ined 3,000 eels without discovering the Syrski organ, we are justified in supposing 

 that many mysteries in the nature of the eel are still reserved for future discoveries. 



t If an eel is opened with a view of finding the Syrski organ, one may easily he 

 deceived by the two fatty bands which have been mentioned several times, and which 

 play so important a part in the treatises of Ercolani and Maggi, who mistook them 

 for the frill-like ovaria. Most people will then think that they are examining a 

 female eel, and will lay it aside. A more thorough examination will leave no room 

 for doubt as to the irregularly indented fatty fold and the frill-like organ. If the lat- 

 ter is not found, one has before him a Syrski eel, and the Syrski organ will be found 



