BULLETIN OF THE UNITED STATES FISH COMMISSION. 85 



eels." These- investigators, without coucerted action, had all at once 

 brought uj) the celebrated issue of the previous century ; this time, 

 however, having specially in view the male organs of the eel, while all 

 were convinced that they had reached a final result by their investi- 

 gations. The results were certainly very peculiar. In the paper of 

 Ercolaui it was claimed that the snake-like folds of fat, which had 

 formerly been noticed near the ovarium, were nothing else than the 

 spermaries of the eel, and that upon the left side of the animal 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 con- 

 sidered 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 ex- 

 pended upon things which are not in the least equivocal, since there 

 was not the slightest trace of structure like that of a spermary. 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 Eauber, of Leipsic 

 has examined these fat cells carefully, and they have also been investi- 

 gated in many eels by the writer. Dr. Jacoby. Never has anything but 

 fat cells and blood vessels been found in them. The so-called sperma- 

 tozoa, described in the work of Maggi and Crivelli, proved to be micro- 

 scopic fat particles or crystalline bodies, such as are commonly found 

 in fat cells. * 



In the meantime, 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. Giinther 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 National History at Trieste, now i^rofessor 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. 



* lu 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 little bodies globular in form. 



