[3] PROPAGATION OF THE EEL. 459 



■we may conclude with a probability bordering on certainty that the 

 SyrsM organs are really the male sexual organs of Anguilla. The male, 

 both of Conger and Anguilla, is therefore considerably smaller than the 

 female. 



In order to ascertaiu the proportion of male to female river eels in our 

 part of the country, and likewise in order to find how far up the rivers 

 the male eels ascend, I have made a series of investigations, which, 

 though interesting in themselves, are by no means sufficient to throw 

 all the light we desire on the life of the eel. This requires further and 

 more exhaustive investigations, for which I would ask the hearty co-op- 

 eration of the members of the German Fishery Association. 



SyrsM\s work,* which marks an era in the history of this investigation, 

 throws some light on the relations between the male and female eels of 

 tke Adriatic, which has been further increased by Jacobtfs investigations 

 at Comacchio. The sexual relations of our North Sea and Baltic eels 

 have hitherto been but little investigated. Mr. Cattie, teacher at the 

 Real school at Arnheim (Holland), found among a large number of eels, 

 measuring 30 to 45 centimeters, 25 per cent, of males. We could not 

 learn, however, where these eels weie caught. 



I have examined : 



(1) 72 eels caught in the Baltic, near Wismar. 



(2) 72 eels from the Great Belt. 



(3) 250 eels from the Elbe, near Cumlosen. 



(4) 40 eels from the Havel, near Wendendorf. 



(5) 137 eels caught near Keuenkirchen in the island of Biigen. 



(0) 40 eels caught on the coast of Schleswig. 



The length of these fish varied from 28 to 42 centimeters. 

 I found among those mentioned under: 



(1) 8 males, or 11 per cent. 



(2) 8 males, or 11 per cent. 



(3) 13 males, or 5.2 per cent. 



(4) No males. 



(5) 61 males, or 44.52 per cent. 



(6) 1 male, or 2.5 per cent. 



From these figures it is apparent that Siebold's assertion that the male 

 eels do not ascend the rivers, but remain in the sea or near the mouth 

 of the rivers, cannot be taken in a literal sense. Cumlosen is near Wit- 

 tenberge, or at least 20 (German) miles from Cuxhafen, at the mouth 

 of the Elbe, and still we here find 5 per cent, males. How large a per- 

 centage of males there may be near the mouth of the Elbe and farther up 

 the river I could unfortunately not ascertain, because the necessary data 

 were wanting. From the Havel, near Havelberg, I unfortunately got 

 only 40 eels, among which there was not a single male ; but we are not 

 justified in concluding from this that there are no male eels in the Havel. 



*"Ueberdie Reproductionsorgaiic der Aale." Vol. LXIX of the li Abliandlungen 

 der k. k. Akademie der Wissenschafteu zu Wien." Part 1. April, 1:74. 



