640 NATURAL HISTORY OF AQUATIC ANIMALS. 



this organ developed into a true testicle, while the one upon the right side shrank up and became 

 functionless. In the work of Crivelli and Maggi, on the other hand, the folds of fat next to the 

 ovary were also considered to be the male organs of the Eel, while the one on the right-hand side 

 of the animal was considered without any doubt to be the male reproductive organ. The last- 

 named authorities described the spermatozoa which they had seen in this stripe of fat upon the 

 right side. Since these stripes of fat were universally found in all Eels, and always in connection 

 with the former, the investigators could come to no other conclusion than that the Eels were 

 complete hermaphrodites. 



The male organ of the Eel, as described by Ercolani, as also by Crivelli and Maggi, shows 

 how carefully investigations may be expended upon things which are not in the least equivocal, 

 since there was not the slightest trace of structure like that of a spennary. The cells of this body 

 in the lining of the stomach next to the ovary are simply fat cells, with all the characteristic 

 peculiarities, just as they are given in all the manuals of histiology. Professor Rauber, of Leipsic, 

 has examined these fat cells carefully, and they have also been investigated in many Eels by the 

 writer, Dr. Jacoby. Never has anything but fat cells and blood-vessels been found in them. The 

 so-called spermatozoa, described in the work of Maggi and Crivelli, proved to be microscopic fat 

 particles or crystalline bodies, such as are commonly found in fat cells. 1 



In the mean time, at Trieste, the question concerning the male organs of the Eel was making 

 a very important advance. Darwin had already expressed the opinion that among nearly all fishes 

 the female was larger than the male. He states that Dr. GUnther had assured him that there was 

 not a single instance among fishes in which the male was naturally larger than the female. This 

 opinion may, perhaps, have induced Dr. Syrski, director of the Museum of Natural History at 

 Trieste, now professor in the University of Lemberg, when he undertook, at the request of the 

 marine officials of Trieste, the determination of the spawning time of the fish which were caught 

 in that region, and was obliged to take up the eel question, to devote his attention especially to 

 the smaller Eels. Dr. Hermes, in behalf of Dr. Syrski, protests against this idea, stating, on the 

 authority of the latter, that the published opinions of Giinther and Darwin were unknown to him 

 prior to the publication of Jacoby's paper. Up to that time every investigator had chosen for 

 investigation the largest and fattest of Eels, thinking that the largest and oldest specimens must 

 have the most highly developed organs of generation. On November 29, 1873, Syrski found in the 

 second specimen which he investigated an individual fifteen inches long, which is now preserved 

 in the museum at Trieste a completely new organ, which had never before been seen within the 

 Eel by any former investigator, although tens of thousands of Eels had been zealously studied.* 

 Syrski published his discovery in the April number of the Proceedings of the Imperial Academy 

 of Sciences, Vienna, in 1874. 3 The most important point of the discovery was stated to be that, 

 in all the specimens of Eels in which the Syrskiau organ was found, the well-known collar-aud- 

 cnff shaped ovary, the female organ of generation, was entirely wanting. It was evident from 

 this that Eels were not hermaphrodites. The question now arose, is the newly discovered organ 



'In a microscopic investigation of fatty tissnes it is very easy for the so-called Brownian molecular movements to 

 be mistaken for moving spermatozoa, especially in fishes, whose spermatozoa, if not very much magnified, show only 

 the head and appear like litt.Ie bod ies globular in form. 



*"I commenced my investigations," writes Syrski, "on the 29th of November last year (1873), and already in the 

 second Eel which I dissected on that day I found the testicles, and therefore a male individual of the Eel. I sent in 

 March of the following year (1874) to the Academy of Sciences in Vienna a preliminary communication, which was 

 read at the public session held (he Kith April, and printed in the reports of the academy." 



'In 1875, Professor von Sielwld found male Eels in the Baltic at Wismar, although this discovery was not at that 

 time made known to the public. They have since been found in the German Ocean, in the Atlantic, and in the 

 Mediterranean. 



