2l8 SOUTHWELL: REPRODUCTION OF THE EEL. 



What we know for certain of the economy of the eel is that in the 

 autumn months great numbers of these fish run down to the sea for 

 the purpose, it is presumed, of propagating their species; but at what 

 age or under what conditions this migration takes place is uncertain. 

 Nor does it appear that this desire to visit the salt-water is even 

 universal, some individuals remaining inhabitants of the fresh-water 

 for an indefinite period ; these are believed to be barren females, but 

 whether their productiveness is only arrested, or their unproductiveness 

 permanent is not known. Should circumstances prevent the eels from 

 going down to the sea they appear restless for a season, but it has never 

 been ascertained that they breed in fresh-water. After leaving the 

 fresh-water, the future proceedings of the eels are shrouded in mystery, 

 but from the fact of immense quantities of young eels ascending the 

 rivers in the spring, it is naturally inferred that they spawn somewhere 

 in the salt-water ; and as the mature eels are never seen returning up 

 stream, the inference is that they perish after having deposited their 

 spawn. A female eel with fully developed spawn has never yet been 

 seen, and until quite recently, as will be seen, the male of the species 

 was altogether unknown. That the mystery which shrouds the 

 reproduction of the eel was fully appreciated by the ancient Greeks 

 is evident from the jocose remark made by several of their poets, to 

 the effect that since all children whose paternity was doubtful were 

 ascribed to Jupiter, he must be considered as the progenitor of the 

 eels also ; be that as it may, from that time till the present day the 

 ' Eel Question ' has in some respects remained an unsolved problem. 

 The theories with regard to the reproduction of the eel have been as 

 numerous as they were strange ; as has been already said, Aristotle 

 taught that they were evolved direct from the watery mud ; more 

 recently Gesner was of the same opinion, but also admits copulation ; 

 others, led astray by the presence of intestinal worms, asserted that 

 the young eels were produced alive, and this has been firmly believed 

 by many from the days of Albertus Magnus to the present time ; 

 others again believed that eels were produced, not from eels, but from 

 certain other fish, {d^ndi even insects), an opinion which also holds its 

 own in many places till the present day. Although Franz Redi and 

 C. F. Paullini both in the 17th century expressed opinions that the 

 procreation of the eel differed in no respect from that of other fishes, 

 still, they did not speak from personal observation, and it was not till the 

 year 1777 that the female generative organs of the eel were at length 

 really discovered and described by Carlo Mondini of Bologna. 

 Mondini's discovery, although independently confirmed shortly after 

 by O. F. Miiller, was denied by the famous anatomist Spallanzani; 

 and it was not till 1850 that the question was definitely settled 



Naturalist, 



