SYRSKI ON THE ORGANS OF REPRODUCTION OF FISHES. 725 



THE REPRODUCTIVE ORGANS OF THE EEL. 



Although the eel is one of the most common fishes, it is, nevertheless, 

 one of the least known. As, even up to the present day, only the female 

 of the eel is known, and this even imperfectly, some naturalists have 

 supposed that the females propagate the species without the help of the 

 male, which mode of reproduction actually takes place in some insects, 

 and is called parthenogenesis ; while others, having recently recognized 

 iu a fatty formation, which is found in the abddminal cavity by the side 

 of the ovaries, the male organs of the eel, have declared it be a hermaph- 

 rodite — i. e., an animal in which both male and female organs are found 

 in the same individual. 



Only a few naturalists have maintained, and as we shall see not with- 

 out reason, that male individuals must be found among the eels. 



Basing their opinion on the reproductive organs, the majority of nat- 

 uralists have with good reason supposed that the eels are oviparous ani- 

 mals, while others, almost exclusively amateurs, have always considered 

 them as viviparous animals. 



It will be of interest to cast a glance on the endeavors of the more 

 distinguished naturalists to find the ovaries and the spermatic organs 

 of the eel, and on some erroneous assertions with regard to this matter, 

 in order to bring out in bolder relief the object in view, viz, to give 

 through a history of a science an outline of this science. 



Aristotle (fourth century before Christ 1 ), the greatest naturalist of 

 antiquity, the founder of zoology, recognized the ovaries of the " grongo" 

 {Conger vulgaris) by the crackling of the eggs when placed over the fire, 

 but maintained that the eel, notwithstanding that its ovaries resemble 

 those of the "grongo" in every respect, is born from worms produced 

 by mud. 



Pliny (first century A. D. 2 ), who, in great part, like the majority of 

 his compatriots, only copied Greek works, especially those of Aristotle, 

 differs from him as regards the reproduction of the eel, maintaining 

 that it rubs itself against rocks, and that from the fragments coming 

 off during this rubbing process the young eels are born. 



Albertus Magnus (thirteenth century A. D. 3 ) accepts Pliny's hypoth- 

 esis, but says that he has heard that eels are also born alive from eels. 



Rondelet (sixteenth century 4 ) asserts that eels are born not only 

 from putrefied matter, but also from eggs produced by the copulation 

 of male and female eels. 



x Aristotle: Tlepl tjbuv laropiag, lib. iii, cap. 10, § 1 ; lib. v, cap. 3, §2, and cap. 9, $ 4 ; 

 lib. vi, cap. 15, § 1-2, and cap. 16, § 6. 



2 C. Plinii Secundi Naturalis historise, lib. ix, cap. 51. 



3 Albertus Magnus: De aninialibus libri viginti sex; written about tbe year 1254, and 

 published at Venice 1495. 



*Bondeletii Universse aquatium historiae pars altera. De piscibns fluviatilibns liberi 

 p. 200, An. 1555. 



